motors vs. servos

Im learning as I go here, and recently learned in another thread that motors and servos are very different in that servos can be driven directly from the board while motors require an H bridge or similar to protect the board.

When designing a beginner robot, what are some other differences between motors and servos that may not be obvious to a newbie?

 

thanks

130 motor

http://www.hobbypartz.com/11h04-19.html