External SSD as good as internal SSD?

[Grant]

I'm going to need to get an SSD one of these days as my storage for gaming isn't enough these days. I want to play Starfield darn it! Anyway I was wondering if external SSD's are just as good as internal SSDs? I want to get an external SSD as I don't want to be bothered to try and install another SSD to my system. I don't even know if my PC can take a second SSD on my motherboard.