EP = Extended Play
usually refers to singles or mini-albums not more than 5 songs.
LP = Long Play
usually refers to albums consisting of 10 or more songs.
in the old days EPs and LPs were used ALOT in describing records.
EPs were the small ones (singles), around 15cm diameter, i have a Beatles She Loves You/I Want to Hold Your Hand single
LPs were the horrendously large ones...about 30cm diameter, i have one of the Beatles A Hard Day's Night LP.