why we use static variables code example

Example: what is static variable

The static variable is used to refer to the common property of all objects 
(that is not unique for each object), 
e.g., The company name of employees, college name of students, etc. 
Static variable gets memory only once in the class area at the time of 
class loading. Using a static variable makes your program more 
memory efficient (it saves memory). Static variable belongs to the class 
rather than the object.