As if we didn’t have enough terminology in this category of devices already, here is another acronym for you some PMP devices, like MP3 players, are also called DAPs, short for digital audio players. Today, digital music players devices come in all shapes and sizes. The category of PMP devices have replaced the larger Walkmans and portable CD players. PMP devices, which is short for portable music player, is a term used to describe any digital portable music player that allows you to download or save digital music files (in MP3 format) directly onto the device, or from from your computer or notebook to play on a PMP. Read on to lean more about MP3 Player Vs iPod. An iPod is really just a brand of MP3 Player, with some exclusive differences.