1. An android toast displays small message to the users about an operation without user input.
2. Toast is displayed in front of the activity and it remains visible for a short time.
3. Normally, android toast is displayed at the bottom of screen, you can also change display position.
4. You can make custom design for toast using xml layout.

For Long Period of Time

Toast.makeText(getApplicationContext(),"This is my toast message",Toast.LENGTH_LONG).show()

For Short Period of Time

Toast.makeText(getApplicationContext(),"This is my toast message",Toast.LENGTH_SHORT).show();