An application programming interface connects software
The interface gives one system a known way to ask another system for something. It also defines the result that comes back.
An application programming interface, or API, is a defined set of rules that lets software systems communicate and exchange data, features, or functionality.
A request follows an agreed contract
Imagine an application that needs a delivery status from another service. It sends a request to a defined endpoint using the expected information. The service checks the request and returns a response in a format both sides understand.
That contract lets each system change internally while keeping the agreed connection stable. When the contract changes, the teams need to coordinate so existing requests continue to work.
APIs support reuse and separation
An API can expose an existing capability instead of making another application build it again. One system might provide customer records, scheduling, or payment status to several approved applications.
Access should be deliberate. The API needs clear permissions, safe handling of incorrect requests, and useful documentation for the people or systems that rely on it.
API terms
- Request
- A message asking another application or service for information or an action.
- Response
- The result returned after a software system receives and handles a request.
- Endpoint
- A defined location through which a particular type of request is sent.
What a useful connection defines
The available action
The interface states what information can be requested or changed.
The expected format
Both systems agree on the shape and meaning of the request and response.
The access rule
Authentication and permission checks limit who or what may use the connection.
Questions about application programming interfaces
API stands for application programming interface. It describes rules that software uses to request and exchange information or actions.
Not usually. A user interface is designed for a person. An API is designed for software to communicate with other software, although people define and manage that communication.
APIs let separate systems share approved data or capabilities through a defined connection. This can reduce repeated work and keep responsibilities separated between applications.
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