What is the library in java

Question

And how to use it

Answer 1

A library in java is package which contains objects,classes and methods as java is platform independent ,we have to import those packages to ru a program for example
import java.lang.*;
this package is automatically imported when you compile a program (it contains primitive datatypes )
import java.util.Scanner;
It will import Scanner for taking users input and there are many more packages for different purposes