What is a critical feature of a RESTful service?

• A. It can only handle synchronous calls
• B. It is stateless in nature
• C. It requires a complex setup
• D. It has a fixed data format

Answer: (B)

A critical feature of a RESTful service is that it is stateless in nature. This means that each request from a client to the server must contain all the information necessary for the server to fulfill that request. The server does not retain any client context between requests, which simplifies the server design and allows for greater scalability.

Being stateless enhances the reliability and performance of the application because each request can be handled independently without relying on previous interactions. This paradigm allows for easier load balancing since requests can be routed to different server instances without the need to share session information or context.

In contrast, synchronous handling of calls is not a defining feature of RESTful services, as they can handle both synchronous and asynchronous requests. A complex setup is also not a requirement of RESTful services, which are designed to be simple and straightforward. Additionally, REST does not enforce a fixed data format; it can support multiple formats such as JSON, XML, or others, allowing for flexibility in data representation. Thus, the stateless nature is what fundamentally distinguishes RESTful services from other web service architectures.