Which of the following formats is commonly used to represent resources in REST?

• A. XML
• B. HTML
• C. PDF
• D. CSV

Answer: (A)

The common format used to represent resources in REST is XML. REST (Representational State Transfer) is an architectural style for designing networked applications, and it leverages various formats to represent resources, which are typically accessed over HTTP. XML, or Extensible Markup Language, is one of the first formats used to encode data in a structured way, making it easily readable by both humans and machines. Its hierarchical structure allows for the representation of complex data structures, which aligns well with REST's need for flexible data representation.

While HTML can represent data, it is primarily designed for displaying content in web browsers rather than for data interchange between systems. PDF is suited for fixed-layout documents and is not typically used for data exchange in RESTful services. CSV, while useful for tabular data, does not support the complex data representations that REST often requires, which is why XML is a preferred choice within RESTful architectures.