Libraries such as jQuery Core substantially minimize the amount of manual coding while programming the core functionality of a web application. The jQuery UI library offers widgets, animations, and advanced effects. The RequireJS library is a module loader that allows you to modularize HTML5 applications. Hundreds of micro libraries are also available that can do just one thing and can be used à la carte (visit MicroJS for details).
Libraries are different from frameworks, which we discuss in Chapter 4. Whereas frameworks force you to organize your code in a certain way, a library simply offers components that allow you to write less code.