Many companies support the SD format because of its high-level of copyright protection. The Secure Disk format is currently available in 32 and 64 MB capacities. Since there isn't an onboard controller chip or surface player connection electrodes, these cards are very durable. These are some of the least expensive flash memory units available. Similar to the hard disk found inside of a computer, although MP3 players usually employ the smaller and thinner kind found in notebook computers.
Hard disk based players offer enormous music storage capacities at very affordable prices.
Hard disks drives are much larger size than flash memory units, and are also more susceptible to Peaking due to their mechanical parts. Internal Flash Only - These players have memory chips inside the case, which are not removable or upgradeable. These are generally bad players since they offer no future expansion. Memory Stick - The Sony Memory Stick has a footprint of a stick of chewing gum, and was developed by Sony to be a versatile multimedia storage format. There are two types of Sony Memory Sticks, and it is important to understand which your player requires.