What is the difference between early rock and roll, and rockabilly?

i hear so many early rock songs (maybelline, rocket 88, rock around the clock, blue suede shoes, etc.) called part of rockabilly music, and i'm confused. What is the functional difference between early rock and roll and rockabilly music?





also, can you give me examples of old rockabilly, meaning before reverend horton heat?|||it was blues, jazz and country coming together that made 'rockabilly' but as it grew more popular and diverse over the years "rock'n'roll" became a more general term, and thus continued to be applied to genres of 'rock' for years.





~Peace~


S.|||rockabilly is like country, its biggest influence is country and rhythm and blues..people like johnny cash,carl perkins,elvis,billy haley where sometimes classified as rockabilly