Pin No 9 10 11 -

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.

Using certain libraries (like the Servo library) can disable PWM functionality on pins 9 and 10 because the library "takes over" the internal Timer 1. Pin No 9 10 11

On an Arduino Uno, pins 9, 10, and 11 are part of a specific group of pins with dual-purpose functionality: All three pins are capable of PWM output (Arduino Reference)