Brands

• Apple's iPod is among the most popular MP3 players, while Microsoft's Zune is also a well-known option. Many other major electronic outfits such as Sony, RCA, and Philips also manufacture MP3 players.
  
  

Files

• All digital music players will play MP3 files, but only some will play MP4 files, which are a rare type of file extension. Mainstream MP3 players such as the iPod will play MP4 files, but others may require updates to do so.
  
  

Storage

• While originally only designed to store a small selection of songs, some MP3 players are now made to hold entire music collections. Archos produces a MP3 player that holds up to 250 gigabytes of data.
  
  

Functions

• At first MP3 players were only designed to play music. Many newer MP3 players also contain video players, alarms, timers, and other useful functions.
  
  

Cost

• MP3 players with less storage space can be purchased for under $50, while others that hold more data, possess more features, and play more file types can cost $400 or more.