jQuery is an open source JavaScript library

jQuery is a JavaScript library which is available for free as open source software, and was developed by John Resig. The extensive framework contains a JavaScript library which provides easy to use and intuitive functions via a cross-browser API. In order the realise them through jQuery the framework code in the HTML source code of the website will need to be bound analog to other external JavaScript files.

One disadvantage of JavaScript can be avoided with jQuery: to ensure browser compatibility, the JavaScript framework offers a cross-browser approach, which saves both time and effort. At the same time, the flexibility and the diversity of the selectors based on XPath and CSS offers the web designer almost unlimited possibilities.

jQuery can implement many features

A large advantage of jQuery is that it can implement many functions by integrating a few lines of code. In addition, one can respond to user behaviour with jQuery as part of an event-driven architecture. Integrating AJAX (Asynchronous JavaScript and XML) lets you establish a bridge to the server, so that, depending on the individual user action or input, information can be sent to the PHP back end and can request the appropriate response from the server for further processing. A common example for an AJAX application is Google Search, in which suggestions automatically appear in your search window as you are typing your question. In addition, typical AJAX effects include sortable tables or drag and drop, as well as many more effects which can be included via a one-line code. jQuery also offers numerous extensions and plugins in addition to the pre-implemented standard functions. These can be easily adapted to a website as desired.

jQuery is one of the most comprehensive JavaScript frameworks with a large and active community which constantly further develops and maintains the library.

You can find more information on jQuery on Wikipedia: https://en.wikipedia.org/wiki/JQuery

and on the official manufacturer’s website: https://jquery.com/