What is a ajax

what is a ajax :- ajax= asynchronous javascript and xml.

ajax is a group of interrelated web development techniques used on the client-side to create asynchronous web applications.with ajax, web applications can send data to, and retrieve data from, a server asynchronously(in the background) without interfering with the display and behavior of the existing page.data can be retrieved using the xmlhttprequest object.

ajax means to increase the web page's usability interactivity and speed.

examples of applications using ajax: gmail, amazon, youtube.

asynchronous -

asynchronous in computer science, is a form of sending/receiving data processing, that permits other processing to continue before the transmission has finished.

javascript -

javascript is used to make a request to the server.once the response is returned by the server.it was originally control the browser, communicate asynchronously and alter the document content that was displayed.

xml -

the data that you receive back from the server will often be packaged up as a snippet of xml, so that it can be easily processed with javascript. this data can be anything you want, and as long as you want.

ajax is based on open standards

ajax is based on the following open standards -

  • browser-based presentation using html and css.
  • data stored in xml format and fetched from the server.
  • javascript/dom.
  • create xmlhttprequest object to exchange data asynchronously with a server.

how ajax works

ajax request/response mechanism complete in three simple steps.

   first step -

  • a user generate an event...
  • create an xmlhttprequest object.
  • send httprequest .

   second step(server side).

  • first process the httprequest.
  • after ceate a response object and send data back to the browser.

   third step(browser side).

  • browser receive the data from server using javascript.
  • the html dom is updated.

importance of ajax.

  • ajax increase the web page's interactivity, speed, and usability.
  • stable, do not crash easily.
  • fast buffering of data.
  • secured transaction.