# Retrieving STEW data

You can access Twitter through the REST (Representational State Transfer) API. To select the response format, change the file extension on almost any request URL to get results in that format. One of the supported formats is (JavaScript Object Notation) JSON, which is used in STEW.

STEW uses JSON (instead of XML, for example) because JSON text can easily be converted into JavaScript objects using the `eval()` function which invokes the JavaScript compiler. JSON is a subset of JavaScript, and therefore the compiler correctly parses the text and produces an object structure. For more information about JSON, see the JSON Web site. Requests are made to Twitter REST APIs by using the `XMLHttpRequest` object. `XMLHttpRequest` is a DOM API that can be used in JavaScript to transfer text data between a server and a browser.

Retrieving data from Twitter comprises the following tasks:

- STEW: implementing a Twitter service

- STEW: presenting content on screens

- STEW: indicating progress