🌟 One of the most common questions in backend job interviews is: *"What’s the difference between SOAP and REST?"* This fundamental concept is crucial for any backend developer to understand.

🎈 **Before REST**, developers used SOAP (Simple Object Access Protocol) as the primary method for enabling communication between server-side (SSR) and client-side (CSR) applications. SOAP relies heavily on XML for data exchange, which made it slow and cumbersome due to the large data payloads.

✨️ Then came **REST APIs (Representational State Transfer)**. REST embraced JSON, a lightweight data format, making data transfer faster and more efficient. JSON’s simplicity as plain text greatly reduced payload size, improving performance.

Key Differences Between SOAP and REST

Both SOAP and REST are web services designed to standardize communication between different servers, but they differ significantly in their approach:

• REST: REST is an *architectural style* that provides a flexible way of interaction. By adhering to a set of constraints, a system can be called RESTful. It focuses on performance, data control, and uses lightweight JSON for communication.
• SOAP: SOAP is a *protocol* that enforces strict rules for communication. It relies solely on XML for data exchange, resulting in slower performance due to larger message sizes.

Advantages of REST

• ✅ More flexible and easier to use
• ✅ Simple to learn with a gentle learning curve
• ✅ Doesn’t require expensive tools or advanced programming languages
• ✅ Faster performance since it avoids using XML for message exchange

Advantages of SOAP

• ✅ Provides built-in security protocols like WS-Security
• ✅ Offers robust error handling options

REST has become the de facto standard for modern web services due to its simplicity, speed, and flexibility, making it the go-to choice for developers building scalable and efficient systems. SOAP, while less common today, is still used in scenarios that demand high levels of security and strict data handling protocols.