To understand the concept and operation of a REST API, picture a library with books, a librarian, and customers who wish to check out, add, update, or remove any number of books. The clients are on one side of this. This is the online application, mobile application, smartwatch, doorbell, or any other interface that uses data access. The data storage, which is usually a database or database server or some other kind of server, is on the opposite side. Our librarian, the REST API, is positioned in the center, receiving, handling, and processing requests and responses. This is how the library operates. When the client sends a request—in this case, to retrieve a resource—the REST API receives it, locates the resource requested, determines what information must be obtained and in what format, builds a representation of the data that complies with the request, bundles it with the response header that contains metadata—such as the resource ID—and hyperlinks to actions that are available...