A java package is a group of similar types of classes, interfaces and sub-packages.Package in java can be categorized in two form, built-in package and user-defined package.There are many built-in packages such as java, lang, awt, javax, swing, net, io, util, sql etc.Here, we will have the detailed learning of creating and using user-defined packages. Advantage of Java Package 1) Java package is used to categorize the classes and interfaces so that they can be easily maintained. 2) Java package provides access protection. 3) Java package removes naming collision. 4) Packages provide reusability of code . 5)To bundle classes and interfaces. 6)We can crate our own Package or extend already available Package.