XML corresponds to a general standard to serialize data of diverse types in a structured way. The XML standard was published in 1996 by W3C and is used intensively to define data structures.

An XML document is known as an element and contains data structures based on content delimited by markers (markups). These markers correspond to labels (tags) that indicate the beginning and end of the structure they delimit.

The XML is a way of representing hierarchical data in a standard text format. When working with XML-based web APIs, we'll be creating XML documents and sending them as the bodies of HTTP Requests and receiving XML documents as the bodies of responses.