All three pins are capable of PWM output (Arduino Reference). This allows you to simulate analog results (like dimming an LED or controlling motor speed) using digital signals.

These three pins (9, 10, and 11) are frequently used as the address lines for 4051/4052 analog multiplexers to expand the number of sensors you can read.

In many standard LiquidCrystal setups, pins 11 and 10 are the default choices for the Enable (E) and Register Select (RS) connections.