What is system.in

Question

Consider this Scanner input example.

Scanner user_input = new Scanner( System.in );

Here Scanner is the CLASS.

Answer 1

System.in is actually an InputStream typically connected to keyboard input of console programs.

Along with it you have direct access also to two other streams System.out and System.err.

System.in, System.out and System.err are initialized by the Java runtime when a Java VM starts.