Two Graphs \(G_1\) and \(G_2\) are isomorphic if there is a bijection \(f : G_1 \to G_2\) that preserves adjacency and non-adjacency.
If \(uv\) is in \(E(G_1)\) then \(f(u)f(v)\) is in \(E(G_2)\).
Two graphs with different degree sequences can’t be isomorphic.
Two graphs with the same degree sequence aren’t necessarily isomorphic.