Deflection, often called distraction or decoy, is an interesting and visually pleasing tactic that helps you reach your goal by forcing your opponent to care about something else than your own target. The following example (black to move) will clarify:
In this position, the black king is the only piece defending the queen on
f8. The move
h7 sacrifices the pawn in
order to distract the king from the defense of the queen.