title: JSON data to web service- how do define expected JSON data
body: <p>I am building a RESTful web service in PHP that accepts JSON as its payload
  .
  Now, my question is, how exactly do I describe to the user the format that the JSON request comes in? I am new to JSON and don't think I have a grasp 100%.</p>
  
  <p>Will the other users system basically create a data structure (such an array) with the key value pairs that I need, encode this in JSON and send it to my web service?</p>
  
  <p>Do I literally give them a copy of what the array needs to look like?
  Thanks!</p>