To better understand how a brushless electric motor works, you need to first understand how a brushed electric motor works. A brushed DC motor has permanent, stationary magnets on the stator and an electromagnetic spinning rotor inside, which spins 180 degrees when electricity is run through it.
The rotor requires the electromagnetic poles to switch to spin a full 360 degrees. This is where the brushes come in. As the rotor spins, the brushes make contact with the stator, and this switches the poles, allowing the rotor to achieve a complete 360 degrees spin.
A brushless DC motor is a brushed DC motor but turned inside out. Hence, a BLDC motor has a permanent magnetic rotor and a spinning electromagnetic stator. This eliminates the need for any brushes to flip the electromagnetic poles.
A computerized BLDC motor control system simply energizes the stator to make complete 360-degree spins.