The magnetic quantum number (m or m1) is the one that indicates the orbit where the electrons are:
The s sublevel has 1 orbital, which is the (0) orbital.
The p sublevel has 3 orbitals, which are the (0), (+1) and (-1) orbitals.
The d sublevel has 5 orbitals, which are the (-2), (-1), (0), (+1) and (+2) orbitals.
The f sublevel has 7 orbitals, which are the (-3), (-2), (-1), (0), (+1), (+2) and (+3) orbitals.