The JavaScript Standard Library is a collection of built-in objects and functions that provide essential tools for developers. It includes features for manipulating data types, handling dates, and performing mathematical operations, among others. This library is part of the JavaScript language itself, making it readily available for use in web development. Developers can access the JavaScript Standard Library to streamline their coding process, as it eliminates the need to write common functions from scratch. Key components include Array, Object, and Function objects, which help manage data and enhance the functionality of web applications.