Singles are generally records consist of two and up to five songs which may contain multiple versions – acoustic, clean (radio edit), remixed, or instrumental. Typically the entire single set lasts 30 minutes.
EP stands for Extended Playlist or simply Extended Play. It is a collection of songs that is not big enough to be a full album. Often, EPs are used as a prequel to an album.
LP means Long Play. It's just another name for a full-length album.
Album refers to the compilation of several tracks (anywhere from 7 to 15) in a single medium such as CD or audio tape.
Mixtapes are compilation of songs, original or cover, usually given out for free for promotional purposes.