>>127276893 (OP) A riff is a repeated melodic line used to accentuate the verses. A hook is a repeated melodic line used to accentuate the chorus. A lick is a repeated melodic line used to accentuate the solo.
A repetitive phrase usually written for electric guitar if we're talking about rock music/metal Sometimes the one riff is the entire song just being repeated over and over like
Day Tripper by The Beatles Satisfaction by the Rolling Stones All Day And All Of The Night by the Kinks Seven Nation Army by White Stripes (though it sounds like a bass guitar riff here)
>>127277572 Not the point of the post, just giving the most obvious examples of guitar riffs that most people have already heard so they know what I'm talking about
A riff is just a distinguishable guitar line, a hook is just whatever the strong point of the song is, and a lick is sort of half-riff, half-solo accentuation.
>>127276893 (OP) the repeated melodic line that is fun to play over and over plastered over the song until it arrives at a bridge where it becomes different then returns to the riffs