Ajax is a set of web development techniques using many web technologies on the client-side to create asynchronous web applications. With Ajax, web applications can send and retrieve data from a server asynchronously without interfering with the display and behavior of the existing page.
Any other technology Ajax also has its own pros and cons. Let's look at some of those.
Allows applications to render without data and fill data as the application gets it from the server.
Gives platform independence to application developers
Faster page renders
More responsive applications
No rerenders of whole pages are needed to update only a single area.
Multiple server requests need more data consumed at the client-side.
Failure of any one request can fail the load of the whole page.
Browsers with JS disabled will not be able to use pages using ajax.