Glossary of API Terms

API

Application Programming Interface. A software intermediary that allows two applications to talk to each other.

API Key

An authorization code passed with an API request via a header or parameter to identify the requester.

Authentication

Identifying the user of the API. Common techniques for authentication include API Keys and OAuth.

Call

A request sent by a user to the API, in the form of a URL string, which invokes a specific action on one particular resource. It may also include additional parameters or header values.

Collection

An API resource that groups other resources together.

Endpoint

The URI that goes after the base URL and points towards the requested API functionality.

The header is the data that is sent preceding the body of an HTTP request or response.

HTTP

Hypertext transport protocol. It is one of the key architectural components behind how web-based content on the Internet is accessed through web browsers.

HTTP Methods

Standard ”HTTP verbs” that identify a type of action that an HTTP client might perform against a resource. Common HTTP methods include:

GET - For retrieving resources from a system with a RESTful API.
POST - For creating resources.
PUT - For updating resources.
DELETE - For removing records.

HTTPS

Hypertext transport protocol secure. It is the same in principle and function as HTTP, but exists when data transmitted via HTTP is encrypted before it is sent.

Hypermedia

Any content type which allows entities to link to each other in a standardized way, making other entities discoverable from a client.

Idempotent

When the results of multiple requests are the same as a single request. GET, PUT, and DELETE are idempotent methods.

JSON

Javascript Object Notation is a data format commonly used for APIs requests parameters and response body.

OAuth

Open standard authorization framework. Grants access on behalf of an end user without directly sharing credentials.

Parameter

An argument sent to the API which helps define the request and expected response.

Proxy

An intermediary for requests from clients and servers providing resources.

RAML

A YAML-based language for describing RESTful and “pragmatically-RESTful” APIs.

Request

A call sent by a user to the API, in the form of a URL string, which invokes a specific action on one particular endpoint. It may also include additional parameters or header values.

REST

Representational state transfer. An architectural pattern for interacting with resources via HTTP methods. It is a form of software architecture that is primarily used for web service design. The World Wide Web is based on REST.

Resource

An object or entity that has a URI and can be manipulated through standard HTTP requests (GET, POST, PUT, etc.).

Response

Data that an API sends back to a user after it is called via a request. The format of an API response is typically JSON (or XML).

URI

Unique Resource Identifier. A string of characters used to identify a resource. The most common form of URI is the Uniform Resource Locator (URL).

URL

Uniform Resource Locator. The unique address for any object or function that can be accessed or invoked on the Web.

Versioning

Assigning a unique identifier to keep track of the state of the API. If breaking changes are made to the API, the version number will be incremented.

XML

Extensible Markup Language. A language used for providing information as well as describing that information, such that programs can interpret data without really understanding the data itself.