Chair: a seat typically having four legs and a back for one person.

...that is one definition of chair, and an accurate one.
Now let's remove 'typically' from the definition for a moment and have some fun.
I have never stopped to count how many chair frames that we carry at Thomasville of King of Prussia, so let us suffice to say a lot.
Choose a frame, a fabric or two or a leather, nail heads or not, double or contrast welt and wood finish.
Now try to call us typical!