The purpose of static methods code example

Example 1: what is static method

A static method belongs to the class rather than the object.
There is no need to create the object to call the static methods.
A static method can access and change the value of the static variable

Example 2: what is static methods and variables

The methods or variables defined as static are shared among all the objects 
of the class. The static is the part of the class and not of the object. 
The static variables are stored in the class area, and we do not need 
to create the object to access such variables. 
Therefore, static is used in the case, where we need to define 
variables or methods which are common to all the objects of the class.
For example, In the class simulating the collection of the students in 
a college, the nameof the college is the common attribute to all the students.
Therefore, the college name will be defined asstatic