The switch is a keyword defined in the java programming language. Keywords are basically reserved words which have specific meaning relevant to a compiler in java programming language likewise the switch keyword indicates the following : 

-- The switch statement in java language enables the user to select the execution of one of code block from a group of similar code blocks on the basis of an expression.

-- Always the switch condition must be evaluated to a char, byte, short or int. then only the execution of the switch case will start.

-- Within a switch case, a case block cannot be terminated itself i.e. it does not have any implicit ending point.  So we provide a break statement at the end of each case block to exit from the switch statement.