SOAP VS REST API

Introduction

SOAP (Simple Object Access Protocol) and REST (Representational State Transfer) are two different approaches used for implementing web services. They differ in various aspects, including their architecture, communication style, messaging format, and usage. Here are the key differences between SOAP and REST APIs.

SOAP (Simple Object Access Protocol)

1. Protocol: SOAP is a protocol that defines standards for structuring messages, using XML for communication between applications.
2. Communication Style: It follows a strict and standardized communication pattern based on the request-response model.
3. Message Format: SOAP messages are XML-based and usually adhere to a specific schema defined by a Web Services Description Language (WSDL). They have a rigid structure with headers and body elements.
4. Transport Layer: It can work over multiple protocols like HTTP, SMTP, or others, using a transport protocol like HTTP or SMTP for message delivery.
5. Security: SOAP provides built-in support for security features such as WS-Security, ensuring message integrity, encryption, and authentication.

REST (Representational State Transfer)

1. Architectural Style: REST is an architectural style that emphasizes a stateless client-server communication via standard operations (e.g., GET, POST, PUT, DELETE) on resources.
2. Communication Style: It follows a more flexible communication style and allows a wide range of data formats (e.g., JSON, XML, plain text) for message exchange.
3. Message Format: REST APIs commonly use lightweight data formats like JSON or XML, but there are no strict formatting rules enforced.
4. Transport Layer: It primarily uses the HTTP protocol, leveraging HTTP methods (GET, POST, PUT, DELETE) to perform CRUD operations on resources.
5. Statelessness: REST is stateless by design, meaning each request from a client to the server must contain all the necessary information, and the server does not retain any session state.

Key Differences Summary

• Message Format: SOAP uses XML-based messages with a defined structure, while REST allows various formats like JSON, XML, or plain text.
• Communication Style: SOAP is more rigid and standardized with a defined protocol, while REST is flexible, simpler, and more adaptable to different use cases.
• Transport: SOAP can use multiple protocols, while REST primarily uses HTTP.
• Statefulness: SOAP is generally considered stateful due to its use of sessions, while REST is stateless.

Both SOAP and REST have their strengths and are suitable for different scenarios based on requirements like security, interoperability, simplicity, and scalability. REST APIs are more commonly used due to their simplicity and compatibility with the HTTP protocol, especially in web applications and mobile development.