Brushless motors are synchronous electric motors that move around electronically. They utilize direct current powering magnets to move the rotor within the stator. Instead of using brushes and a commutator, the motors use a step motor controller. It creates a rotation that in turn converts electrical energy into mechanical energy unlike the brushed or conventional motor.
A brushless motor loses the brushes and the commutator. And the locations of the magnets and windings are reversed: The magnets are on the conventional motor shaft and the copper windings of the armature are fixed and surround the shaft. Instead of brushes and a commutator, a small circuit board coordinates the energy delivery to the windings.Because the electronics communicate directly with the stationary windings, the tool adjusts according to the task—which is why the companies market these as "smarter" tools. For example, if you're using a brushless drill to drive screws into Styrofoam, it more readily senses the lack of resistance (compared with a brushed motor) and begins to pull only what little charge it needs from the battery. If the tool then starts putting 3-inch screws into mahogany, it will adjust accordingly and draw more current. By contrast, a brushed motor will always run as fast as it can while in use.
In addition, brushless motors can be more powerful overall. Because the copper windings are on the outside of the motor configuration, there is room to make them larger. Brushless motors also don't have the friction and voltage drop that brushes create by dragging against the spinning commutator. This physical contact results in a continuous energy loss during the operating process.