What Is an API?

Introduction

An Application Programming Interface (API) is a structured method that allows two software systems to communicate with each other. APIs form the backbone of modern digital communication. Whenever a mobile app retrieves data from a server or a website interacts with an external service, an API is involved.

Core Principle

APIs expose data or functionality in a controlled, secure and standardized way. This allows developers to build complex systems without needing to access internal logic.

API Types

1. REST API

The most common type of API. Uses HTTP and JSON.

2. SOAP API

XML-based, often used in enterprise systems.

3. GraphQL

Allows clients to request exactly the data they need.

4. Webhooks

Used for real-time push notifications.

Use Cases

• Mobile apps
• Web applications
• Payment systems
• IoT devices
• Mapping and geolocation services
• Third‑party integrations

Security

API security involves:

• API keys
• OAuth 2.0
• Rate limiting
• HTTPS enforcement
• JWT authentication

Conclusion

APIs are essential to modern software. They enable integration, scalability and secure communication between systems.