A package in Java is used to group related classes. Think of it as a folder in a file directory. We use packages to avoid name conflicts, and to write better maintainable code.

Packages are divided into two categories:

  • Built-in Packages (packages from the Java API)
  • User-defined Packages (create your own packages)

The library is divided into packages and classes. Meaning you can either import a single class (along with its methods and attributes), or a whole package that contains all the classes that belong to the specified package.

To use a class or a package from the library, you need to use the import keyword:

Syntax

import package.name.Class;   // Import a single class
import package.name.*;       // Import the whole package

Example

import java.util.Scanner;  // Import the Scanner class
import java.util.*;        // Import all classes from java.util package

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter your name:");
        String name = scanner.nextLine();
        System.out.println("Hello, " + name);
        scanner.close();
    }
}

In the example above, we imported the Scanner class from the java.util package to read user input.

Happy coding!