They all have different name brands, so far I understand that some are quad core and dual core, but are the quad cores are all the same? Do they have more power like computer CPU's? I installed Kodi on my computer and downloaded several add-ons so I'm learning the software. Is more ram and nand better? Should it have a memory slot?
Is the graphic card part important and how do I know which one is better?
Am I better off using an old computer to run Kodi?
Thanks for the help
They are literally exactly 'like your computer'. To be fair, so is your phone, router, cable box, and probably TV itself. They all have CPUs, they all have RAM, and they all have permanent storage. Heck, I just did a firmware update on my TV. The only difference is that these devices are generally locked down, and they don't generally encourage consumers to much about with the system software (usually referred to as 'firmware') and if they have software available they are usually from app stored and the apps generally operate in a pretty locked down environment. I'm an open software and hardware geek, but ultimately there is value in having appliance like platforms that are hard for inexperienced users to muck up.
In the case of an Android TV box, honestly, if you're just streaming Netflixs or Youtube, and maybe playing some media files, then pretty much any device will do. Check the reviews to make sure it works, and has a new version of Android, but after that don't worry about it. If you want to 'seriously game' on it then you'll want those extra cores, RAM, and a better GPU. For 'just streaming and casual games' anything with 2 cores will do, and you only really need the two cores to prevent any one process from eating 100% of the CPU causing an embarrassing pause.
I actually have a Nexus Player hooked to my TV. It's convenient for Netflix and streaming, and comes with a simple bluetooth remote. Beyond that I have my home server that is a Linux box hooked to the TV, that logs into a guest account. Basically the Nexus Player saves my from having to fart around to get Netflix to work under Linux, and gives me a physical Android device to develop against. Plus it's easy for company to use. Then people who know what they're doing can use a 'grown up OS' on the TV for with things like VLC, Firefox, LibreOffice, etc (that doubles as a redundant, encrypted, and backed up file and print server for my LAN).