CSS and JavaScript optimization
Every web application has CSS and JavaScript files. Nowadays, it is common that most applications have lots of CSS and JavaScript files to make the application attractive and interactive. Each CSS and JavaScript file needs a browser to send a request to the server to fetch the file. So, the more the CSS and JavaScript files you have, the more requests the browser will need to send, thus affecting its performance.
Each file has a content size, and it takes time for the browser to download it. For example, if we have 10 CSS files of 10 KB each and 10 JavaScript files of 50 KB each, the total content size of the CSS files is 100 KB, and for JavaScript it is 500 KB—600 KB for both types of files. This is too much, and the browser will take time to download them.
Note
Performance plays a vital role in web applications. Even Google counts performance in its indexing. Don't think of a file that has a few KBs and takes a 1 ms to download because when it comes to performance...
