(magnitude as seen from Earth adjusted for Earth atmosphere)
Apparent magnitude is
a magnitude-style (logarithmic) measurement of brightness
indicating the brightness as seen from Earth, adjusted
only to cancel the effects of Earth atmosphere. The
commonly-used apparent magnitude is calibrated to indicate the ratio
of the object's apparent brightness with that of the
star, Vega, i.e., with 0 taken as Vega's apparent magnitude
(Vega system).
Some such apparent magnitudes:
The unmodified term magnitude likely most often means
apparent magnitude. Magnitudes cited for observations through
filters are generally apparent magnitudes. Cited apparent
magnitudes can refer to the visible light magnitude (generally
that through the V filter), or alternately, a bolometric magnitude
(sometimes cited as the apparent bolometric magnitude).
These can differ substantially and for precision, you need to note
which.