LiPo batteries will have a discharge rating and this is noted on the battery label as a "C" rating (25C, 30C, 50C, etc). In simple terms, the C rating is like a "fuel pump" - the bigger that number is, the better the fuel pump and the better the battery will perform.
Keep in mind that power is drawn from the motor of the RC depending on load, voltage, weight, gearing, etc., it's not the battery that pushes the power to the motor.
This means that using a high C rating battery in a basic power system won't necessarily make it faster or more powerful, but will allow for a more constant power delivery, keep battery temps down and may even increase run times. However, using a low C rating in a high performance power system will actually hinder performance, stress out the battery which will increase battery temps and can reduce run times.
There are usually battery recommendations available when buying any RC, but you can always contact us for suitable batteries if in doubt.