A chord progression at the end of a phrase. There are several type of cadences.
The Imperfect authentic cadence. V - I like the perfect authentic cadence but one of the chords is inverted or the uppermost note in the tonic chord is not the tonic. Two examples:
Imperfect because both chords are inverted.
Imperfect because the tonic chord uppermost note is not the tonic.
Half cadence or semi cadence. A chord progression that ends in the V (dominant):
Deceptive or interrupted cadence. V (dominant) - vi or V - IV:
Plagal cadence. IV (subdominant) - I: