I will try to make this brief, basically, what sort of computer hardware is optimal for a digital artist's desktop or laptop?
First and foremost, you need a lot of RAM, while you can get away with having a disguised toaster for a computer and painting on it, you will most likely end up with really slow runnning painting software no matter what you use having more RAM will more often than not largely solve this. You need a minimum of 8GB of RAM to have any shot at a good painting experience on modern computers, and if you have such low amounts of RAM make sure you turn off all background applications while you paint, you have a lot more breathing room however if you have 16GB which is why that is what I recommend. Some artists will need even more.
Secondly but perhaps no less important you need a good, multicore CPU ideally you want an Intel i7, AMD Ryzen 5 or AMD Ryz