- term: 2-up description: The default mode of viewing images on GitHub. - term: alternate object database description: >- Via the alternates mechanism, a repository can inherit part of its object database from another object database, which is called an "alternate". - term: AMI description: >- Amazon Machine Image. A virtual appliance for use with the Amazon Elastic Compute Cloud. - term: anonymized image URL description: >- An anonymous URL proxy for each image that hides your browser details and related information from other users. - term: apex domain description: A root domain that does not contain a subdomain part. - term: API description: >- Application programing interface. A set of clearly defined methods of communication between various software components. - term: API token description: >- A token that is used in place of a password in scripts and on the command line. - term: app description: >- Third-party service that integrates with GitHub. This generally refers to OAuth applications or GitHub Apps. This is also referred to as an app. - term: application description: >- Third-party service that integrates with GitHub. This generally refers to OAuth applications or GitHub Apps. This is also referred to as an app. - term: argument description: 'In GraphQL, a set of key-value pairs attached to a specific field.' - term: AsciiDoc description: >- A text document format for writing notes, documentation, articles, books, ebooks, slideshows, web pages, man pages and blogs. - term: assets description: 'Individual files such as images, photos, videos, and text files.' - term: Atom feed description: A lightweight XML format allowing for easy syndication of web content. - term: audit log description: >- In an organization, the audit log includes details about activities performed in the organization, such as who performed the action, what the action was, and when it was performed. - term: avatar description: >- A custom image users upload to GitHub to identify their activity, usually along with their username. This is also referred to as a profile photo. - term: AWS description: Amazon Web Services. A secure cloud services platform. - term: Azure description: A Microsoft cloud-computing platform. - term: Azure DevOps description: >- A Microsoft product offering source code hosting, issues, CI/CD pipelines, and other developer services. The on-premises version was formerly known as Team Foundation Server. The cloud-hosted version was formerly known as Visual Studio Team Services. - term: bare repository description: >- A bare repository is normally an appropriately named directory with a .git suffix that does not have a locally checked-out copy of any of the files under revision control. That is, all of the Git administrative and control files that would normally be present in the hidden .git sub-directory are directly present in the repository.git directory instead, and no other files are present and checked out. Usually publishers of public repositories make bare repositories available. - term: BFG repo cleaner description: BFG. A third-party tool that cleanses data from your Git repository history. - term: blob object description: 'Untyped object, e.g. the contents of a file.' - term: bot description: A software application that runs automated tasks. - term: Bundler description: A way to manage Ruby gems that an application depends on. - term: camo description: >- An SSL image proxy to prevent mixed content warnings on secure pages served from GitHub. - term: chain description: >- A list of objects, where each object in the list contains a reference to its successor (for example, the successor of a commit could be one of its parents). - term: CIDR notation description: A compact representation of an IP address and its associated routing prefix. - term: CLI description: Command line interface. - term: CNAME record description: >- Canonical Name record. A type of resource record in the Domain Name System (DNS) used to specify that a domain name is an alias for another domain (the 'canonical' domain). - term: conditional request description: >- In the REST API, an HTTP method that is only responded to in certain circumstances. - term: connection description: 'In GraphQL, a way to query related objects as part of the same call.' - term: core Git description: >- Fundamental data structures and utilities of Git. Exposes only limited source code management tools. - term: CPU description: Central processing unit. - term: credential helper description: A program that stores and fetches Git credentials. - term: creole description: >- A lightweight markup language, aimed at being a common markup language for wikis, enabling and simplifying the transfer of content between different wiki engines. - term: CSV description: Comma-separated files. - term: DAG description: >- Directed acyclic graph. The commit objects form a directed acyclic graph, because they have parents (directed), and the graph of commit objects is acyclic (there is no chain which begins and ends with the same object). - term: dangling object description: >- An unreachable object which is not reachable even from other unreachable objects; a dangling object has no references to it from any reference or object in the repository. - term: data pack description: >- Storage and bandwidth package that users can purchase. Each data pack provides 50 GB of bandwidth and 50 GB for storage. - term: DELETE description: A type of method in the REST API - term: DHCP description: >- Dynamic Host Configuration Protocol (DHCP). A client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway. - term: directive description: >- In GraphQL, a way to affect the execution of a query in any way the server desires. - term: directory description: The list you get with the command "ls". - term: disaster recovery description: >- Also known as DR. Tools and processes that recover technology infrastructure and systems following a human or natural disaster. - term: DNS provider description: >- A company that allows users to buy and register a unique domain name and connect that name to an IP (Internet Protocol) address by pointing your domain name to an IP address or a different domain name. - term: DSA description: Digital Signature Algorithm. A processing standard for digital signatures. - term: DSA key description: Public and private keys used in DSA. - term: Early Access Program description: >- A GitHub program that individuals and organizations enter into to receive pre-released features. - term: EBS description: >- Amazon Elastic Block Store. Provides persistent block storage volumes for use with Amazon EC2 instances in the AWS Cloud. - term: EC2 description: >- Amazon Elastic Compute Cloud. A web service that provides secure, resizable compute capacity in the cloud. - term: edge description: 'In GraphQL, connections between nodes.' - term: EIP description: Elastic IP. A static IPv4 address designed for dynamic cloud computing. - term: ElasticSearch description: A search engine based on Lucene. - term: evil merge description: >- An evil merge is a merge that introduces changes that do not appear in any parent. - term: exclude description: >- After a path matches any non-exclude pathspec, it will be run through all exclude pathspec (magic signature: ! or its synonym ^). If it matches, the path is ignored. When there is no non-exclude pathspec, the exclusion is applied to the result set as if invoked without any pathspec. - term: FIDO U2F description: >- An open authentication standard that strengthens and simplifies two-factor authentication using specialized USB or NFC devices based on similar security technology found in smart cards. - term: field description: 'In GraphQL, a unit of data you can retrieve from an object.' - term: file system description: >- Linus Torvalds originally designed Git to be a user space file system, i.e. the infrastructure to hold files and directories. That ensured the efficiency and speed of Git. - term: flame war description: A heated and abusive discussion online between users. - term: fragment description: 'In GraphQL, reusable units that let you construct sets of fields.' - term: GCE description: Google Compute Engine. - term: gem description: A command line tool that can install libraries and manage RubyGems. - term: Gemfile description: A format for describing gem dependencies for Ruby programs. - term: GET description: A type of method in the REST API - term: geoJSON description: A format for encoding a variety of geographic data structures. - term: GitHub Marketplace Developer Agreement description: An agreement users sign when using GitHub Marketplace. - term: GPG description: >- GNU Privacy Guard. Encryption software that you can use to encrypt (and decrypt) files that contain sensitive data - term: GPG key description: An encryption key used with GPG. - term: hash description: synonym for object name - term: head description: >- A named reference to the commit at the tip of a branch. Heads are stored in a file in $GIT_DIR/refs/heads/ directory, except when using packed refs. - term: HEAD description: A type of method in the REST API - term: headers description: >- In the REST API, a required component of the message that defines the metadata of the transaction. - term: health check description: >- A way to allow a load balancer to stop sending traffic to a node that is not responding if a pre-configured check fails on that node. - term: HTTP verb description: An HTTP method. - term: Hyper-V description: >- A Microsoft product that creates virtual machines on x86-64 systems running Windows. - term: hypermedia description: 'In the REST API, links from one resource state to another.' - term: icase description: Case insensitive match. - term: implementation description: 'In GraphQL, how an object inherits from an interface.' - term: index description: >- A collection of files with stat information, whose contents are stored as objects. The index is a stored version of your working tree. Truth be told, it can also contain a second, and even a third version of a working tree, which are used when merging. - term: index entry description: >- The information regarding a particular file, stored in the index. An index entry can be unmerged, if a merge was started, but not yet finished (i.e. if the index contains multiple versions of that file). - term: introspection description: >- Also referred to as "introspective." A way to ask a GraphQL schema for information about what queries it supports. - term: iPython notebook description: >- A web-based application that captures the whole computation process: developing, documenting, and executing code, as well as communicating the results. - term: JIRA description: An Atlassian product that tracks issues. - term: Jupyter notebook description: Notebook that contains both code and rich text elements. - term: kernel description: A computer program that is the core of a computer's operating system. - term: kramdown description: Jekyll's 3.0.0 default Markdown processor. - term: LDAP description: Lightweight Directory Access Protocol. - term: linter description: A program that verifies code quality. - term: Liquid description: A templating language that's used to load dynamic content. - term: load balancer description: >- A device that acts as a reverse proxy and distributes network or application traffic across a number of servers. - term: media type description: A two-part identifier for file formats and format contents. - term: MediaWiki description: >- A free and open-source wiki software written in the PHP programming language that stores the contents into a database. - term: Mercurial description: 'A free, distributed source control management tool.' - term: metadata description: A set of data that describes and gives information about other data. - term: MIME-type description: >- Multipurpose Internet Mail Extensions. A way of identifying files according to their nature and format. - term: mutations description: >- In GraphQL, a way to define GraphQL operations that change data on the server. - term: nameserver description: >- A server on the internet specialized in handling queries regarding the location of a domain name's various services. - term: NFC description: >- Near Field Communication. A set of communication protocols that enable two electronic devices, one of which is usually a portable device such as a smartphone, to establish communication by bringing them within a certain range of each other. - term: node description: >- An active electronic device that is attached to a network, and is capable of creating, receiving, or transmitting information over a communications channel. - term: node description: 'In GraphQL, a generic term for an object.' - term: NTP description: Network Time Protocol. - term: object description: >- The unit of storage in Git. It is uniquely identified by the SHA-1 of its contents. Consequently, an object can not be changed. - term: object database description: >- Stores a set of "objects", and an individual object is identified by its object name. The objects usually live in $GIT_DIR/objects/. - term: object identifier description: synonym for object name - term: object name description: >- The unique identifier of an object. The object name is usually represented by a 40 character hexadecimal string. Also colloquially called SHA-1. - term: object type description: >- One of the identifiers "commit", "tree", "tag" or "blob" describing the type of an object. - term: octopus description: To merge more than two branches. - term: onion skin description: >- A way to view images on GitHub by decreasing the opacity of an overlaid replacement image. - term: OOM description: Out of memory. - term: Open Stack description: A software platform for cloud computing. - term: OpenSSH description: >- A suite of security-related network-level utilities based on the Secure Shell (SSH) protocol. - term: ordered list description: A numbered list. - term: Org description: >- A plain-text system for keeping notes, maintaining TODO lists, planning projects, and authoring documents. - term: pack description: >- A set of objects which have been compressed into one file (to save space or to transmit them efficiently). - term: pack index description: >- The list of identifiers, and other information, of the objects in a pack, to assist in efficiently accessing the contents of a pack. Pathspecs are used on the command line of "git ls-files", "git ls-tree", "git add", "git grep", "git diff", "git checkout", and many other commands to limit the scope of operations to some subset of the tree or worktree. - term: parameter description: >- In the REST API, data that is either sent in the request or received in the response as part of an input or output parameter. - term: parent description: >- A commit object contains a (possibly empty) list of the logical predecessor(s) in the line of development, i.e. its parents. - term: passphrase description: >- A sequence of words or other text used to control access to a computer system, program, or data. - term: PATCH description: A type of method in the REST API - term: pathspec description: Pattern used to limit paths in Git commands. - term: PEM description: Privacy Enhanced Mail - term: persistent identifier description: >- Also known as Digital Object Identifiers (DOIs). Globally unique numeric and/or character strings that reference a digital object. Persistent identifiers can be actionable in that they enable a user to access the digital resource via a persistent link. - term: pickaxe description: >- An option to the diffcore routines that help select changes that add or delete a given text string. With the --pickaxe-all option, it can be used to view the full changeset that introduced or removed, say, a particular line of text. - term: plugin description: A software component that adds a specific feature to an existing program. - term: Pod description: Plain Old Documentation. A mark-up language used by perl developers. - term: pointer file description: A reference that points to an actual file. - term: port description: An endpoint of communication in an operating system. - term: priority question description: >- Questions for GitHub support from organizations on the Business plan. Questions must meet the criteria set forth by GitHub to qualify as a priority question. - term: priority response description: >- Answers from GitHub support for priority questions from organizations on the Business plan. - term: polling description: >- Regular automatic checks of other programs or devices by one progam or device to see what state they are in. - term: POST description: A type of method in the REST API - term: Pre-release Program description: >- GitHub program that allows users to apply new features and functionality before they're officially launched. - term: PUT description: A type of method in the REST API - term: QCOW2 description: An image format. - term: QR code description: >- Quick Response code. A barcode is a machine-readable optical label that contains information about the item to which it is attached. - term: queries description: 'In GraphQL, a way to ask for specific fields on objects.' - term: rate limit description: The process by which an API rejects requests. - term: RDoc description: An embedded documentation generator for the Ruby programming language. - term: reachable description: >- All of the ancestors of a given commit are said to be "reachable" from that commit. More generally, one object is reachable from another if we can reach the one from the other by a chain that follows tags to whatever they tag, commits to their parents or trees, and trees to the trees or blobs that they contain. - term: ref description: >- A name that begins with refs/ (e.g. refs/heads/master) that points to an object name or another ref (the latter is called a symbolic ref). - term: reflog description: A reflog shows the local "history" of a ref. - term: refspec description: >- A "refspec" is used by fetch and push to describe the mapping between remote ref and local ref. - term: relative link description: A link that is relative to the current file. - term: remote-tracking branch description: A ref that is used to follow changes from another repository. - term: REST API description: >- An API that defines a set of functions so developers can perform requests and receive responses via HTTP. - term: reStructured text description: A what-you-see-is-what-you-get plaintext markup syntax and parser system. - term: revision description: Synonym for commit. - term: rewind description: >- To throw away part of the development, i.e. to assign the head to an earlier revision. - term: root endpoint description: 'In the REST API, the directory that all endpoints are under.' - term: RSA description: Algorithm used to encrypt user data using a public key and a private key. - term: RSA key description: A private key based on the RSA algorithm. - term: SAML description: >- Security Assertion Markup Language. An XML-based, open-standard data format for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider. - term: SAN description: Subject Alternative Name - term: Sass description: A CSS extension language. - term: schema description: Metadata that tells us how our data is structured. - term: SCIM description: >- System for Cross-domain Identity Management. An open standard for automating the exchange of user identity information between identity domains. - term: SCM description: Source code management (tool). - term: SCSS description: A CSS extension language. - term: service account description: >- A special user account that an application or service uses to interact with the operating system. - term: SHA-1 description: >- "Secure Hash Algorithm 1"; a cryptographic hash function. In the context of Git used as a synonym for object name. - term: shell description: A user interface for access to an operating system's services. - term: shallow repository description: >- A shallow repository has an incomplete history some of whose commits have parents cauterized away (in other words, Git is told to pretend that these commits do not have the parents, even though they are recorded in the commit object). This is sometimes useful when you are interested only in the recent history of a project even though the real history recorded in the upstream is much larger. A shallow repository is created by giving the --depth option to git-clone(1), and its history can be later deepened with git-fetch(1). - term: SMS description: A text message. - term: SMTP description: Simple Mail Transfer Protocol. A standard for email transmission. - term: SNMP description: Simple Network Management Protocol. A protocol for network management. - term: spam description: Unsolicited communications from another user. - term: SSD description: Solid-state drive. - term: SSH description: >- Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. - term: ssh-agent description: A program to hold private keys used for public key authentication. - term: SSH Key description: >- SSH keys are a way to identify yourself to an online server, using an encrypted message. It's as if your computer has its own unique password to another service. GitHub uses SSH keys to securely transfer information from GitHub.com to your computer. - term: SSH key fingerprint description: >- Identifies and verifies the host you're connecting to and is based on the host's Public key. - term: SSL description: Secure Sockets Layer. - term: static site generator description: >- A program that generates an HTML-only website using raw data (such as Markdown files) and templates. - term: String description: An object type that denotes plain text - term: STL file description: >- STL (STereoLithography) is a file format native to the stereolithography CAD software created by 3D Systems. - term: subdomain description: >- A customizable and optional part of a domain name located before the root or apex domain that looks like a domain prefix. - term: submodule description: >- A repository that holds the history of a separate project inside another repository (the latter of which is called superproject). - term: subproject description: >- A project that's developed and managed somewhere outside of your main project. - term: Subversion description: An open source version control system. - term: sudo mode description: >- A way for users to run programs with the security privileges of another user. Users still provide their own password and are authenticated. - term: superproject description: >- A repository that references repositories of other projects in its working tree as submodules. The superproject knows about the names of (but does not hold copies of) commit objects of the contained submodules. - term: support bundle description: >- A gzip-compressed tar archive that contains important logs from your GitHub Enterprise instance. - term: swipe description: A way to view portions of your GitHub image side by side. - term: symlink description: >- A file that contains a reference to another file or directory in the form of an absolute or relative path and that affects pathname resolution. - term: symref description: >- Symbolic reference: instead of containing the SHA-1 id itself, it is of the format ref: refs/some/thing and when referenced, it recursively dereferences to this reference. - term: tag description: >- A ref under refs/tags/ namespace that points to an object of an arbitrary type (typically a tag points to either a tag or a commit object). A tag is most typically used to mark a particular point in the commit ancestry chain. - term: tag object description: >- An object containing a ref pointing to another object, which can contain a message just like a commit object. It can also contain a (PGP) signature, in which case it is called a "signed tag object". - term: Team Foundation Server description: >- The former name of a Microsoft product that provides source code management and other team services. Now known as Azure DevOps Server. - term: Textile description: >- A lightweight markup language that uses a text formatting syntax to convert plain text into structured HTML markup. - term: TLS description: Transport Layer Security. - term: token description: >- Can be used in place of a password. Tokens can be personal access tokens, OAuth tokens, or API tokens. - term: topoJSON description: An extension of GeoJSON that encodes topology. - term: TOTP application description: >- Time-based One-Time Password. This type of application automatically generates an authentication code that changes after a certain period of time. - term: tree description: >- Either a working tree, or a tree object together with the dependent blob and tree objects (i.e. a stored representation of a working tree). - term: tree object description: >- An object containing a list of file names and modes along with refs to the associated blob and/or tree objects. A tree is equivalent to a directory. - term: TSV description: Tab-separated files. - term: two-factor authentication description: >- Also called 2FA. An extra layer of security that not only requires a standard log in procedure with a username and password but also an authentication code that's generated by an application on the user's smartphone or sent as a text message (SMS). - term: UFW description: Ubuntu's default firewall configuration tool. - term: unmerged index description: An index which contains unmerged index entries. - term: unordered list description: A bulleted list. - term: unreachable object description: 'An object which is not reachable from a branch, tag, or any other reference.' - term: URI description: >- Uniform Resource Identifier. A string of characters used to identify a resource. - term: UTF-8 description: A character encoding capable of encoding all possible Unicode code points. - term: variable description: 'In GraphQL, a way to make queries more dynamic and powerful.' - term: VAT ID description: A value added tax identification number used for tax purposes in the EU. - term: verified email address description: >- An email address tied to a personal account that the user has verified is valid with a security confirmation process. - term: virtual machine description: >- An application environment that is installed on software and imitates dedicated hardware. Also called a VM. - term: VPC description: Virtual private cloud. A virtual network dedicated to your AWS account. - term: VPN description: Virtual private network. - term: VMware description: >- A Dell product that provides cloud computing and platform virtualization software and services. - term: allowlisted description: >- A list or register of entities that are being provided a particular privilege, service, mobility, access or recognition. Entities on the list will be accepted, approved and/or recognized. - term: working directory description: The directory of files you're currently working in. - term: working tree description: >- The tree of actual checked out files. The working tree normally contains the contents of the HEAD commit’s tree, plus any local changes that you have made but not yet committed. - term: WYSIWYG description: >- What You See Is What You Get. An acronym meaning the text on the screen looks exactly as it will when it's rendered. - term: XenServer description: A virtualization platform. - term: YAML description: >- A human-readable data serialization language that is commonly used for configuration files. - term: Continuous Integration description: Also abbreviated as CI - term: Continuous Delivery description: Also abbreviated as CD