jQuery is a JavaScript library that provides an easy way to manipulate the DOM, as well as make Ajax requests. It was created by John Resig in 2006 and has since become one of the most popular libraries on the web.
One of the main benefits of jQuery is that it abstracts away the complex cross-browser code needed to manipulate the DOM. This makes it much easier for developers to write code that works consistently across different browsers.
jQuery also includes a number of built-in functions that allow you to easily create animations, handle events, and perform AJAX requests. Additionally, there are thousands of plugins available that provide extra functionality such as Infinite Scrolling or Drag & Drop.