Barre chord
fret 1, E shape133111
Fm is the F minor chord. Its notes are F, A♭ and C. The lowered third gives this triad its darker color.
133111
x-8-10-10-9-8
Numbers show frets from the low E string to the high e string; x means don't play that string.
Fm is the ii chord in E♭ major, the iii chord in D♭ major and the vi chord in A♭ major. That makes it a natural fit in songs written in those keys.
Every F, A♭ and C on the first 12 frets. The filled dots are the root, F. Build your own shape from any nearby group.
Other F chords
Other minor chords