What Is an API and How Does It Work

Short answer

An Application Programming Interface defines how software components communicate. APIs expose functionality without revealing internal implementation details.

How it works

A client sends a request to an API endpoint. The server validates the request, performs the operation, and returns a structured response, often in JSON.

Example

A weather API exposes GET /forecast?city=Paris. The client receives temperature and conditions without accessing the weather database directly.

Why it matters

APIs enable modularity and integration. They allow mobile apps, websites, and third-party services to share data and functionality securely.