What are the differences between net MD walkman and MP3, what are their advantages and disadvantages compare to each other?

There are quite a few dfferences between the two storage types. I'll start with describing the two, then I'll talk about their advantages and disadvantages.

MP3 players have the ability to be one of the smallest audio media carrying devices ever created - some have been made to be built into an ordinary wrist watch. They generally take less power then other media devices, since there are no moving parts in them. Older MP3 players simply connected to your computer by a cord, but the new ones have a Universal Serial Bus (USB) connector built right into them. These new ones will act like a virtual drive, and to add music to them, all you have to do is go into Windows Explorer and drag-and-drop your music onto the drive, thus requiring no software, and it can be used on any computer.
The drive in an MP3 player, usually some sort of flash memory, can come in all sorts of sizes, from as low as 32 MB (around 1 CD) to 40 GB (over 500 CDs). The legendary iPod from Mac comes in the 15 GB, 20 GB, and 40 GB sizes, but if you ask me, nobody needs that much space for mobile audio. How much you can fit on your MP3 player depends on the bit-rate of your MP3 files. Most MP3s run at 96 Kbps, because any more is just pointless: your ears can't tell the difference. That size will stick around 60 minutes of music per 32 MB. Roughly 1 CD's worth.

MD (Mini Disc) audio is slightly different. A player, similar to a portable CD player, is used to play a 2 inch x 2 inch disc. Your limitation of how much music is on the disc isn't by size, but by time, since all of the music is re-encoded prior to being stuck on the disc. The standard size for a disc is 80 minutes, but with some encoders, you can double that time. It depends on your MD player brand and capabilities. Software is required to be installed on your computer prior to you sticking any music on your discs, and therefore requires some computer knowledge as to how to work the program, since some of these programs (especially the Sony one) can be somewhat complex. An alternative to getting from a computer, some MD players offer a Line In jack that allows you to record from other devices providing you have an 1/8", double-male stereo cord (No idea what I'm talking about? Ask the tech-person when you buy the player).

Ok, now to break them down. If you're going to want to exchange music with other people, the MD player is better since all you have to do it spit out the disc. It's also handy for recording stuff off the radio through the headphone jack. If you're not the computer whiz, take the MP3 player, but check before-hand that it acts as a virtual drive, and requires no software. Keep in mind that most MP3 players do require software, so you have to check that in advance.

Ok, I might add more later, but my fingers are getting tired. ;D Feel free to ask any more, specific, questions.

I recently brought a Hardisk jukebox player, and when I placed the music on to the player and, played the music it seemed to be scrunched up and not very loud, and this music was from CD, so my question is, If I brought a really top spec portable CD player would the sound quality be better then a MP3 Hardisk player? And this there a difference or am I dojn something wrong, thanxs ryan