Mining - the process of matching hashes, that is - generating a new combination based on the previous one, but as accurately as possible.
There are a lot of algorithms for that, it's not important for us. What is important for us is that the higher the search speed (H/s, MH/s, GH/s), the bigger the reward (or higher the probability of it.
For this case, anything that can "count" - CPU, video card or special ASIC-mainers. CPU in this regard is completely inefficient, because its cores are designed for consistent execution of complex, but "low-quantity" tasks. Also it is necessary to use special programs that help to do this quickly and efficiently, such as bzminer
Video card
A graphics card, unlike a CPU, has several thousand cores that are designed for fast parallel computing.
RTX 3060Ti - one of the most popular video cards from miners
The main characteristics for a miner if he wants a video card for mining (they usually mine ETH and all currencies under him):
Energy efficiency
video memory size (DAG-file on ETH is not cancelled)
Cooling system quality
PCB quality
As for "power" I think nobody needs to explain. More powerful graphics card produces more hashes, less powerful one produces less hashes.
The choice of miners in 2020-2021 were video cards Palit GTX 1660 Super and Palit RTX 3060/3060Ti, because with a relatively low price tag, midgets from Palit had the same set that could give more expensive versions of video cards.