When it comes to GPUs, NVIDIA’s GeForce GTX 10-series have made it possible for manufacturers to trim down the overall size of gaming laptops without sacrificing features like battery life, making them powerful and portable. AMD's also basically non-existent in the mobile space these days too, so if you're shopping for a cheap gaming laptop you're probably getting one with an Nvidia GPU under the hood.
One of the typical features that sets apart a gaming laptop is a colorful, backlit keyboard. These vary quite a bit from model to model, with more elaborate backlighting going hand-in-hand with higher prices and a higher general level of other components. Almost all budget gaming laptops will employ single-color backlighting (most often, red or white) to keep costs down. The next step up is lighting programmable by zone, with three or four blocks of the keyboard independently customizable in different colors, but this is not common in budget machines. Keyboards with per-key, individually programmable lighting are the province of high-end machines only.