Finite state machinesautomatons recognize regular languages. The advantage of regular languages is that it is usually trivial to express them formally.
FSA #1
$$L(M_1) = \left\{ a^kb^lc^m | k > 0, l \geq 0, m \in \{ 0, 1 \} \right\}$$
FSA #2
$$L(M_2) = \left\{ a^kb^lc^m | k > 0, l > 0, m \in \{ 0, 1 \} \right\}$$