DevNet Associate key terms

A distributed version control system that tracks changes to files in a repository, letting developers commit snapshots locally, branch their work, and share changes through remote repositories such as GitHub or GitLab.

An independent line of development inside a Git repository, created so work on a feature or fix can proceed without affecting the main codebase until it is merged back.

A state Git reports when two branches change the same lines of a file in different ways, requiring a developer to choose or combine the changes manually before the merge can finish.

A request to merge one branch into another, usually in a hosted repository, that shows the proposed diff and lets teammates review, comment on, and approve the changes before they are integrated.

An automated check that exercises a single function or class in isolation, verifying that a specific input produces the expected output so regressions are caught quickly during development.

A coding practice where the developer first writes a failing test for the desired behavior, then writes the smallest amount of code that makes the test pass, and finally refactors the code.

An automated sequence that builds, tests, and often deploys code whenever changes are pushed, so integration problems and defects are found early and releases become repeatable rather than manual.

A lightweight text-based data format built from objects, arrays, strings, numbers, booleans, and null; it is the most common payload format for REST APIs because both humans and programs can read it easily.

A human-readable data serialization format that uses indentation instead of brackets or braces, widely used for configuration files, CI pipeline definitions, and infrastructure automation playbooks.

An isolated directory holding its own Python interpreter link and installed packages, so a project's dependencies do not conflict with other projects or with the system-wide Python installation.

An HTTP-based interface where resources are identified by URLs and manipulated with standard methods, using stateless requests that carry all the information needed to process them.

The verb in an HTTP request that states the intended action, such as GET to read, POST to create, PUT or PATCH to modify, and DELETE to remove a resource.

A three-digit number in an HTTP response summarizing the outcome, grouped into classes such as 2xx success, 3xx redirection, 4xx client error, and 5xx server error.

The property that repeating the same request leaves the server in the same state as sending it once; GET, PUT, and DELETE behave this way, while POST generally does not, which matters when retrying.

A control that caps how many API requests a client may make within a time window and reports remaining quota, protecting the service and telling callers when to slow down.

Splitting a large API result set into smaller pages controlled by parameters such as limit, offset, or a continuation cursor, so responses stay fast while clients iterate through all records.

A callback URL supplied by a client that a service calls with an HTTP POST when an event occurs, reversing the usual pull model so an application is notified instead of polling.

An HTTP-based protocol that exposes YANG-modeled device data as resources, letting clients read and change configuration with GET, POST, PUT, PATCH, and DELETE, typically returning JSON or XML.

A RESTful, token-authenticated interface to Cisco Meraki cloud-managed networks, where organizations, networks, devices, and clients are addressed as URLs so automation can read and change cloud settings.

Cisco's intent-based network controller, offering a REST API and SDKs for automating device discovery, fabric provisioning, policy, and assurance data across campus and branch networks.

A collection of RESTful interfaces to Cisco Webex collaboration services that lets applications create and manage spaces, messages, meetings, and users on behalf of an authorized account.

The network operating system running on many Cisco switches, routers, and wireless controllers; besides the CLI it supports programmatic access through NETCONF, RESTCONF, and YANG models.

Cisco's data-center SDN architecture in which a controller manages policy across leaf-and-spine switches; its REST API accepts and returns JSON or XML for automating tenants, endpoint groups, and contracts.

An authorization framework in which a user or application grants a client a scoped access token without sharing the password; the client then presents that token, often as a bearer credential, to call APIs.

A secret string issued to identify a calling application, sent in a header or query parameter; it is simple to use but identifies the app rather than a user and must be protected like a password.

Storing and distributing credentials such as API keys, passwords, and certificates through a controlled vault or environment variables instead of hard-coding them in source code or scripts.

A packaged, immutable filesystem plus metadata, built from a recipe such as a Dockerfile, that runs identically on any host with a compatible container runtime.

A protocol that encrypts and authenticates traffic between a client and server, forming the S in HTTPS and using certificates so the client can verify it is talking to the intended party.

An XML-based protocol that runs over a secure SSH session to retrieve and edit configuration on network devices using datastore operations such as get-config, edit-config, and commit.

A data modeling language describing the configuration and state data of a network device, providing the schema that NETCONF, RESTCONF, and model-driven tooling use to validate and structure requests.

An agentless automation tool that connects over SSH or an API to run declarative playbooks of tasks, commonly used to configure network devices and servers from a central control node.

Managing devices through structured YANG models and protocols such as NETCONF and RESTCONF instead of scraping CLI text, so automation receives predictable, validated, machine-readable data.

Keeping the desired state of networks, servers, and cloud resources in version-controlled definition files that tools apply automatically, making deployments repeatable, reviewable, and recoverable.

The router address a host sends traffic to when the destination is on a different subnet; without a correct gateway, a device can reach local peers but nothing beyond its own network.

A notation expressing an IP network as an address plus a prefix length, such as 192.168.10.0/24, where the prefix states how many leading bits identify the network portion.

A Layer 2 broadcast domain created logically on switches so that ports on the same physical equipment can be separated into different networks without running separate cabling.

A hierarchical system that resolves human-readable names into IP addresses so applications can reach services by name; a resolution failure often looks to users like a total outage.

A protocol that automatically supplies hosts with an IP address, subnet mask, default gateway, and DNS servers, so devices can join a network without manual configuration.

A technique that rewrites source or destination IP addresses, and often port numbers, as packets cross a router, commonly letting many private hosts share one public address.

An ordered list of permit and deny rules applied to router or firewall interfaces that matches traffic on addresses and ports to decide which packets are forwarded and which are dropped.