In Java, a package is a mechanism to group related classes, interfaces, and sub-packages into a namespace. It provides a unique namespace for each type it contains, allowing classes in the same package to access each others package-private and protected members. Packages are used to prevent naming conflicts, organize classes belonging to the same category or providing similar functionality, and write maintainable code.
Java has two types of packages: built-in packages and user-defined packages. Built-in packages are part of the Java API and contain prewritten classes that are free to use, such as java.lang, java.io, and java.util. User-defined packages are created by developers to group their own classes and interfaces.
To create a package in Java, the package keyword is used at the beginning of the source file, followed by the package name. If the package name is specified, the file must be in a subdirectory called name, where the directory name must match the package name.
In general, a package can contain classes, interfaces, enumerations, and annotation types. When we compile a package, a new folder is created with the same name as the package, and the compiled class files are stored in that folder.
In summary, a package in Java is a way to organize related classes and interfaces into a namespace, providing a unique namespace for each type it contains. It is used to prevent naming conflicts, organize classes belonging to the same category or providing similar functionality, and write maintainable code.
