Is Ajax asynchronous?

After looking at Ajax, it looks a little excited indeed. It is a responsive web UI, partial refresh rather than overall refresh ......

But after reading it, I thought about it. Is this really what I need? Although Asynchronization can make the UI respond quickly, I feel a little bit of a taste of changing the changes. Even if the request is asynchronous, the data required by the real user still needs to be passed back after the server completes processing, what is the difference between this and that synchronous users wait for a request? OK. You can say that the user can continue to perform some operations during the waiting period. That's true, however, if the user jumps to the page when the server has not completed the processing, will the server still call back the previously defined function after the server completes the request? If yes, an error may occur because the page has already been redirected. If not, Asynchronization will be meaningless.

Technology should always follow the application, and the application needs decide everything. Computer software development, especially web-based technology, is too much and too tired. It seems that struts is correct at the beginning, but the price is to write a very simple function, so we need to coding a bunch of classes, XML files, and JSP files. Is this necessary in most applications? In my opinion, the only thing that I use most in struts is struts's international framework for interface text. We can put all the strings in one properties, in this way, it is easy to implement internationalization. In fact, it is easy to implement this part. Write a class by yourself and load all the strings to the memory when the web application starts, then put it in the context of the application. When JSP is used, it will be okay to directly reference it. I have read the struts source code, and he just did this. Back to Ajax, how many web applications do we write require Asynchronization?

It may have something to do with my scope of work. None of the Web applications I write are website type. Haha, they are generally dedicated software, but the interface is web, now, instead of spending a lot of time and energy learning, testing, and porting ajax to my application, we can put this time in learning CSS, Dom, and JavaScript, learn how to make a brighter and more interactive web interface.