Advantage of JQuery

1. Open Source

jQuery is developed by and available in the Open source community, thus it is free to use (like most programming languages). There are plenty of developers, designers and webmasters who can enrich you with so much data that you might get confused what all to use. And there are so many plugins already available which can be easily be used for enhancements on a website. jQuery is generally better for complex development functionality, as compared to javascript, which should used for smaller, front-end tasks.

2.Huge Library

From simple items like border radius, image slider, design forms, to placing grids, and display audio/videos... the resources are endless. These plugins are so simple to use that you can can plug and play the code in just a few minutes.  Pay attention to the demos of the plugins on the various websites to give you the feel of the change you would want to do. In addition, there are many pre-made themes available which developers can pick up quickly and design the page for CMS like WordPress and Drupal.

3. Cross-platform

jQuery is great at handling all cross-browser issues. Some Javascript's have problems in early versions of IE and Firefox. But, jQuery has helped eliminate this issue. This avoids having to write different codes for different browsers. It results in high efficiency and less hassles.

4. SEO

jQuery effects are like Flash and can't really be utilized for SEO. The larger benefit of jQuery is that the files are very small and can be easily optimized for site speed. This is especially beneficial for mobile-friendly sites too. There are plugins to display images and audio-video files easily on a page instead of embedding them directly. With site speed being a fairly important part of Google's algorithm, it's important to note that whereas jQuery cannot make absolute steps toward Google domination, it is much better than using a bunch of Javascripts.