Differentiate between Synchronous and Asynchronous Ajax requests.

Synchronous Ajax requests: In this, the script stops and waits for the server to reply before continuing. In the web application world, one has to happen after the other, i.e. the interaction between the customer and the server is synchronous. Synchronous is not recommended as it blocks/hangs the page until the response is received from the server.

Asynchronous Ajax requests handle the reply as and when it comes and allows the page to continue to be processed. Under Asynchronous, if there is any problem in the request it can be modified and recovered. The request doesn’t block the client as the browser is responsive. The user can perform other operations as well.