Actually static is a very big topic in java. You can ask specific thing in that you can't understand.
static variable: When a variable is declared with the static keyword, its called a class variable. All instances share the same copy of the variable.
static Method:When a method is declared static, it can be called/used without having to create a object first. Static Methods Cannot Access Non-Static Variables
static class: you instantiate the inner classes independently of the main enclosing class
Life is easy because we write the source code.....