This is a sixteenth note.
It lasts for one quarter of a beat.
There are four sixteenth notes in one beat.
There are 16 sixteenth notes in one bar of * time.
Once you are comfortable playing sixteenth notes on a single pitch, try using them to play the C major scale, as shown in the following example.
Here are some example which makeuse of sixteenth notes. Take them slowly at first and count as you play. Tap your foot on each beat and remember that there are four sixteenth notes per beat. Because the notes are closer together here, you will need to breathe after a quarter note, or even an eighth note sometimes.