The server exposes a representation of the resource’s state, which basically means that we show the resource’s data (i.e. state) in a neutral format. This is similar to how the data for a webpage can be stored in a database, but is always sent to the browser in HTML format.
This means that the client doesn’t care about the server’s internal implementation of the resource. The server might store the resource data in an Oracle database, a flat file, or it might even be generated by a procedure call; it doesn’t matter to the client. All the client cares about is the representation that it gets from the server.