a package is a group/dir of similar types of classes, interfaces and sub-packages

some packages in java
- java.lang: used to bundle the fundamental classes NO IMPORT REQUIRED
- java.io: used for the classes for input, output functions which are bundled in
this package

java.lang sub-package contains:
- System.class
- String.class

Two Types Of Packages:
- Built-in package already available in java language
- the programmer can create their own package which
can be imported to other classes

java.util sub-package contains:
- ArrayList.class
- Map.class

java.awt sub-package contains:
- Button.class

Use a package when you want access protection.
Also java package removes naming collision

How to create a package

package omruti;

How To Create subpackage

package omruti.fortnite;

How To Compile a java package

javac -d directoryName javafilename.java

How to instantiate a function within a package

//we always write the package name before the class name
java.util.Scanner s = new Scanner(System.in);

The above code can be tedious sometimes

import java.util.Scanner;
Scanner s = new Scanner(System.in);

Important Concepts with Access Modifiers in Regards to Packages

1- A Private class's methods/functions are not accessible to any other class
within the same package nor to any other package

2- A public class's method/function is accessible to any other class within
the same package and to any outside packages

3- A Protected class's method/function is accessible within the same package
to any other class but not to another class within another package

4- Default access modifier's methods/functions are accessible to any other
class within the same package but not to any other class defined in another 
package