An Application Programming Interface, or API, is a tool that makes it easier for developers to access software from another application.
Browser APIs, a type of Web API, are provided by browsers to give developers access to information that the browser can access from users’ computers.
For example, the Web Audio API is a browser API that provides a powerful and versatile system for controlling audio on the Web.
Third-party APIs are apps that provide some type of functionality or information from a third-party, usually a company.
For example, the OpenWeather API is a third-party API that provides in-depth weather information.
All third-party and Web APIs provide documentation for how to use the API.
Some third-party APIs require an API key which is a special token that is given to a developer to interact with the API. These API keys are unique and should be kept secret.
When a successful request is made to an API, data is sent back. Most APIs return data in the form of JSON, and it is up to developers to decide how to consume it.