What are packages in JAVA

Packages are nothing but folders containing similar java classes, interfaces, enumerations, annotations.
So if you have n java classes that are focused on one functionality, we generally store those classes in one folder. This is called as a package.

Advantages of creating packages in JAVA:-

• We can easily search the classes, interfaces etc.
• It helps in naming convention.
• It prevents name conflicts.

If you have a package transport wich contains Bike class.

You can access class using below methods

• Class name -> transport.Bike.java
• Path name -> transport/Bike.java

Generally source/class files are stored in reverse company domain name.

for example - 

com\amazon\transport\Abc.java

com.amazon.transport\Abc.class

//ABC.java - source file

package com.amazon.transport; 

public class Abc{ }

class Xyz{ }

When you compile the Abc.java
$javac -d . Abc.java

This will create 2 class files.

com\amazon\transport\Abc.class

com\amazon\transport\Xyz.class

To import all classes defined in package transport, you can use below statment

import com.amazon.transport.*

To tell JVM where it should find the classes, we can set the classpath variable giving the path your class files are stored.