jQuery is a fast, small, and feature-rich JavaScript library. It makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers. If you’re new to jQuery, we recommend that you check out the jQuery Learning Center.
If you’re updating to a newer version of jQuery, be sure to read the release notes published on our blog. If you’re coming from a version prior 1.9, you should check out the 1.9 Upgrade Guide as well.
Note that this is the API documentation for jQuery core. Other projects have API docs in other locations: