Not exactly. In the parlance of RC motors, "brushless motor" simply denotes an AC motor, whereas a brushed motor is a DC motor. I really dislike the terms "brushless" and "brushed" terms, as they are confusing and don't really describe the fundamentals of the motor.

A servo motor can be either AC or DC, and is usually comprised of the drive section and the resolver/encoder. The term "servo" simply means the motor is capable of feedback position control. A good exmaple of servo motor are those used in CNC machines. The electric motors used to power RC airplanes, either brushed or brushless, are definitely NOT servo motors.