What does LP and Double LP mean when talking about records?

LP= Long Playing. Originally, back in the early to mid 1900's, records were played at 78 rpm (Revolutions per Minute), and you only could fit one song on each side of the record. These are commonly called 78s. The earliest of these records had the recording on one side only...the other side was left blank! Around 1948, a process was invented where one could slow the speed of the record down, and narrow the grooves, and thereby fit more than one song on to each side of a 10" or 12" disc. These were considered "long playing" records, and so the term "lp" was coined. (By the way, the term "album" was coined from taking more than 1 78 and releasing it in a book form...or an "album"). A Double lp simply is to release a recording onto 2 long playing records. One of the biggest selling double lps released was Peter Frampton's "Frampton Comes Alive", and you can find one at any garage sale or flea market!