Variables that have only one copy per class are known as static variables. They are not attached to a particular instance of a class but rather belong to a class as a whole. They are declared by using the static keyword as a modifier. For example: static type varIdentifier; where, the name of the variable is varIdentifier and its data type is specified by type. Static variables that are not explicitly initialized in the code are automatically initialized with a default value. The default value depends on the data type of the variables.