There are four primary types of cadences:

Perfect Cadence

A perfect cadence is the progression from the dominant chord to the tonic (V-I).



Imperfect Cadence

An imperfect cadence is any cadence ending on chord V. As it sounds incomplete the cadence is considered a weak cadence. There are several forms of the imperfect cadence but the most common is I-V:



Plagal Cadence

The plagal cadence is the progression of the subdominant chord to the tonic (IV-I). As the plagal cadence has no leading note the progression is weaker than the perfect.



Interrupted/Deceptive Cadence

A cadence from the chord V to any other chord other than I. The most common application of this is V - vi. This cadence is used to delay the perfect cadence, here is a full example:



Variations

• Authentic - An authentic cadence is when both chords of the cadence are in root position.
  
• Inverted - An inverted cadence is when the last chord of a cadence is inverted.