All groups of order 6 are isomorphic to either $S_3$ or $\mathbb{Z}_6$.
Without knowing that, I was trying to derive how many structurally distinct groups of order 6 exists by constructing the multiplication tables.
And I came upon the following statement on this question:
Having all non-identity elements have order 2, means the group is abelian.
Is this trivial? Could I know that before trying to build the table?