Identifiers : In Java , names boxes are called variable names. The word "variable" means that changing, because we can change the value inside the box. We can't change its name,
The name of the Variable fall in the category of something is known as identifiers.Identifiers are names given to things in Java. It is includes variables, methods, classes, etc.
Identifier is a first word must be an underscore, a letter, or a dollar sign. it can contain a digits and naming should not be started with digits. whitespace cannot allowed.Identifier is a case sensitive
