Is a bison a cow?

Excuse me, but could you clarify something for me? I've come across the question, "Is a bison a cow?" and I'm a bit confused. I understand that both bison and cows are members of the bovine family, but are they truly the same thing? I mean, they look somewhat similar, but I'm wondering if there are any key differences that separate them as distinct species. Could you help me understand this better? Thank you in advance.