The hard drive of a computer refers to the fact that the computer memory can retain any and all stored information that was put in - even if it is not powered. The non-volatile examples would be hard disks, floppy disks, read-only memory, etc. This would be opposite than RAM, as it loses everything when shut down.

In regard to the MP3 players, or the digital audio players, there are three main drive types a person should know about: the MP3 CD players; the flash-based player that are low-storage devices; and the hard drive-based players or digital jukeboxes. The last one refers to a device that reads any digital audio files from a hard drive. They are considered better as they have higher capacities, ranging from 128M to 8GB. Solid state with no moving parts, they are considered very resilient. It is projected that flash-based media will surpass the hard drive based players, making them obsolete. Images and video media support is becoming quite accepted among hard drives, due to their capacity and physical size. So with all this in mind, it is time to look at how it relates to the MP3 devices and what you want to buy.

The first thing in picking the right hard drive player is to decide just what you are hoping to get out of the device. Are you looking for a hard drive player that can hold a few audio books for a long trip? Are you looking for a hard drive player that can hold your entire music collection? Or are you just looking for a hard drive player that looks pretty? Hopefully it's not the last option or you may want to consider a nice, shiny walkman. If you are simply looking for a hard drive player that will hold an audio book or two then one of the more affordable players with a few gigs of memory should do just fine. If you are looking for something to store your entire music collection on then you need to do a little math. Currently you can find hard drive players with memory space from 1GB of memory all the way to 60GB of memory - so, how much do you need?

With a massive music collection, you are looking at a pretty high end hard drive player, unless you are willing to weed out all of the songs you don't want off of every CD. This takes forever and is strongly discouraged. It is difficult for some to grasp just how much music you can fit on to each size of hard drive player, but a general rule of thumb is 500 songs per gigabyte. So 4GB will give you roughly 2,000 songs and 60GB will give you around 30,000 songs.

Finally, decide what types of extras are important to you in a hard drive music player. Do you want to be able to view photos, watch videos, or do both? Would you like to have an FM tuner or recorder? Is optional data storage important to you? Is it important for you to have accessories (belt clips and cases, etc.) for your hard drive player? You may not want any of these, but it is best to choose which you would want because almost all of the MP3 devices will come with something "extra" now to entice buyers into their stores. So, you might as well get something now that you will use later on.