When I first started working with APIs, I struggled to understand why there were so many ways to design them. Over time, I learned that both architectural styles and communication protocols can make a big difference in how systems interact and evolve.

Here’s a look at six of the most common ones:

1/ RESTful

• Standard HTTP methods, stateless communication.

• Simple, scalable, widely supported.

• Integrates with caching and HTTP tools.

2/ SOAP

• XML-based, built-in error handling and security.

• Enterprise-grade, reliable, robust.

• Ideal for complex transactions.

3/ GraphQL

• Query language, fetches only required data.

• Flexible, reduces over/under-fetching.

• Single endpoint, clear schema.

4/ gRPC

• High-performance, Protocol Buffers serialization.

• Lightweight, efficient, real-time communication.

• Multi-language support.

5/ WebSockets

• Persistent, bidirectional communication.

• Ideal for real-time updates (e.g., chats).

• Low latency, reduces server load.

6/ MQTT

• Lightweight messaging protocol.

• Designed for low-bandwidth, IoT devices.

• Minimal bandwidth, reliable message delivery.

These six styles are among the most common, but there are others out there as well. Would you add any that you think are important to the Visual?