5.30Functional analysis of a familiar pattern

Take:

C | G | Am | F

Roman numerals:

I | V | vi | IV

Functionally:

tonic → dominant → tonic-family → predominant

Notice something interesting:

V doesn't resolve directly to I.

It goes:

V → vi

That's the deceptive-cadence relationship.

Then IV keeps the motion going.

This progression is incredibly common in pop because it loops smoothly rather than giving a strong final cadence every four chords.