Say $G=Z_4 \oplus U(4), H = \langle (2,3) \rangle, K= \langle (2,1) \rangle$. Determine the isomorphism class of factor groups $G/H$ and $G/K$.
I am able to see that $H , K$ are isomorphic but I don't understand what is meant by isomorphism class.
I also computed order of all cosets in the factor set and found that there are equal number of elements of each order $2,4$. So they are isomorphic, but is there a better way to do this.