hard to get any more simplified. they are both complex topics with multiple uses and reasons to implement them. you'll have to do some reading and start learning all the variables. i can't summarize it down to a couple of sentences
tor is pretty complicated overall and has many uses, some legal, some not. overall idea is anonymity while using it. though that has been shown to not be the case. but it is still pretty anonymous unless you're doing the illegal stuff and then we've seen over and over how easy it is for the various governments to figure who is who and bust it wide open.
vpn started as a way to log into and work on the company servers from elsewhere. secure, encrypted connected between the 2. it's turned into a commercial product aimed at privacy and getting around geoblocking.
different uses really.
so what is it you want to do that you feel like you want to be anonymous while doing it? in either case, illegal activity is easy to sniff out and neither solution will keep you safe while doing it.