What is AJAX?

Asynchronous JavaScript and XML(AJAX) is a combination of technologies used particularly for developing web applications. So, it’s more than what is considered a programming language and or any specific technologies. By developing the web applications, the users can feel a good dynamism around their visit web applications, and excess workload can be lifted up with the tie-up of these technologies under AJAX. 

What’s the use of AJAX?

AJAX is useful in simplifying tasks that are complex and time-consuming, which makes users stay away from figuring out the functionality of an application. With AJAX in the forefront, it has been found extremely essential and useful for the following purposes:-

  • Web pages can be updated without reloading an entire page. 
  • You can retrieve information from the server in the background without affecting the current activity of the users. 
  • You can create dynamic web applications which can be interactive and faster than it used to be. 

What are the technologies used in AJAX?

As AJAX is a set of technologies which is being worked out for a web application, the technologies used include :-

  • Javascript- used for adding dynamic content to the webpage, which ensures client-side functionality and is used mostly to create AJAX web applications. 
  • DOM(Document Object Model)- used for styling the content with its interactivity and displaying in mind. 
  • XML, HTML, and XSLT- for interchanging and manipulating the data. 
  • XMLHttpRequest- an API that enables a data exchange asynchronously between web browsers and servers. 
  • XHTML and CSS- Extensible HTML(XHTML) and Cascading Style Sheets(CSS) are markup languages dealing with the styling of content by positioning the text and deciding suitable colors for the text as well as the background.

How does AJAX work?

Before AJAX came into use, majority of the browsers used to send an HTTP request to the servers whenever a user was in the step of engaging or performing an action in the application. Only when the web server receives the request, processes and sends it to the browser, that webpage is refreshed with newly added data. Irrespective of the scale of changes, browsers were to reload an entire page, which affects the users on the other side. 

To resolve these issues, AJAX was used. It followed certain steps to avoid the unnecessary actions that were earlier used. They are:-

  • It uses a JavaScript function to create an XMLHttpRequest object on the browser. 
  • It then collects the page information in XML format, from the XMLHttpRequest sent that is already sent to the web browser. 
  • The server processes the request and sends the requested data. 
  • The browser updates the data without refreshing the page. 

Drawbacks of AJAX

  • Majority of the web browsers don’t support JavaScript or  XMLHttpRequest object, which limits the functionality of AJAX. 
  • Bookmarking and navigation are to be planned in advance for the AJAX-enabled pages. 
  • Security and user privacy concerns are more likely to be prone to AJAX applications. 
  • Sole reliance on AJAX can harm the searchability of web pages.