so I ended up doing a "Google" on Rif vs Lick
here's it's answer:
The Difference Between a Riff and a Lick:
Riff:
A riff is thematic (a what??). It serves as the main section for a song.
Think of Satisfaction for example or Smoke On The Water. A riff is often repeated and developed, sometimes with variations, sometimes in different keys, but a riff is always recognisable as the main idea or main part of the song.
A riff is what makes the song 'recognisable' and distinctive. p.s. thematic just means a theme! ; )
Lick:
A lick or solo is a portion of a riff, so it is not the main distinction in the song, just part of the song. A lick is often incomplete in musical terms (but don't worry too much about that).
On it's own the lick doesn't usually become the main part of a song like a riff does. But if a lick forms a theme (like a continuous main section in a song), essentially the lick becomes a riff.
Because a lick isn't the main theme, it doesn't have that same association with the song, and so it becomes transferable: a lick can be used in other songs without necessarily having to allude to the original lick. Clever!
More info:
Take a pentatonic scale as this example. If you focus on just one Pentatonic Scale, you can easily create lots of difference licks from just one scale. Or you could create a distinctive riff that runs through the song from just one scale.
Riffs are the main 'sound' or theme of a song, and licks are just parts of a song - like a verse, or chorus.