Checking the existence of the same user during user registration: One of the relatively simple but at the same time useful uses of Ajax is checking the website database when new users are registered. Suppose a user has already Qatar Phone Number Data registered on your website with a certain username, now another user wants to register with the same username, and you probably don't want two users to register with the same username. In the usual case, you can check the database after the user presses the registration button and in the code related to the registration button, and if there is the same username, stop the new user registration operation or send a message to the user. In any case, in this way you will have a complete postback, which may not be very pleasant for the user.
But with the help of Ajax, you can remove the postback operation and increase the work speed. It is enough to write a static function in the server code that checks the database and returns a specific value if there is a similar username. Then you can call this function through JQuery in the client function related to exitingor in the client function related to clicking the registration button, and if there is the same username in the database, give a message to the user and of course allow the code to run. Don't give the server either. In this way, there will be no need to refresh the page, you can use the same technique in other ways. You've probably noticed how comments appear on the Facebook website or how images appear in Google Image Search.