jQuery - functionality and comfort in building a frontend layer
It is an open source library, which means that anyone can improve it by pointing out bugs in the code and by creating and sharing their own functionalities. For this reason, many useful extensions to the library are being developed, including jQuery UI, which streamlines the work of frontend developers to build user-friendly intuitive interfaces. It also simplifies unit testing through specially developed modules and responsible libraries such as jQuery - Qunit. Meanwhile, the library's API further relieves developers of the need to check for errors and inconsistencies in code across browsers.