Package is a mechanism to group related classes ,interfaces and enums
in to a single module.
Package can be declared using the following statement :
Syntax : package <package-name>
Coding Convention : package name should be declared in small letters.
package statement defines the namespace.
The main use of package is
1) To resolve naming conflicts
2) For visibility control : We can define classes and interfaces that are
not accessible outside the class
// import <package> -> Imports the whole package
// import <package>.<class> -> Imports a certain class
import java.util.Scanner;