I'm making a game but I'm having a hard time deciding on a clear difference between a spell and a skill. any advice?

So i recently quit WoW, and honestly at this point have played so many other "mmorpgs" and most didn't do it for me some i stuck with. swtor, neverwinter, rift, tera were okay but not for me. dcuo destiny 2, eso are some i didn't mind.

My main issue is in my opinion the wow group dynamic of tank takes dmg and aggros enemies to them dps do dmg and just dont be stupid and healers know when to do massive healing and when to do min healing and dps to help, is my favorite thing. being a long time healer i enjoy the roles.

Most games that have these role don't always capitalize on them. EX eso upon release i know its a bit better now but at first tank and healer roles meant next to nothing and that bothered me.

Was asking to see if anyone has found and games that do the role based combat reall...

I play a few different games but rn I don't have anybody to play RL with I don't usually use my mic it's not that good I'm just ok at the game but I have fun playing I'm not sure if this is self promotion or if it meant streamers but if it is lmk I'll take it down