When information is returned from a REST web service call, what types of files can it be?

When information is returned from a REST web service call, it is typically formatted in a structured data exchange format that is easy for programming languages to parse and generate. JSON (JavaScript Object Notation) and XML (eXtensible Markup Language) are two of the most widely used formats for this purpose.

JSON is favored for its lightweight structure and ease of use, particularly in web applications where JavaScript is often the programming language of choice. It is simple to read and write, making it a popular option for API responses.

XML, on the other hand, offers a more verbose structure that supports attributes and complex hierarchies, which can be advantageous for certain types of data representation and is extensively used in enterprise applications and configurations.

Both JSON and XML are commonly supported by RESTful web services, allowing clients to choose the format that best suits their needs. In this context, the correct answer emphasizes these two primary formats that are frequently utilized in REST API responses.