U disk is the abbreviation of USB disk, and the USB drive is just a U disk homophonic name. U disk is a kind of flash memory, so also called flash disk. The biggest feature is: small and easy to carry, large storage capacity, inexpensive. is one of the major mobile storage devices. Now the general U disk capacity has 1G, 2G, 4G, 8G, 16G or greater, the most common in the price of 8G, for example, dozens of yuan can be bought. U disk capacity has a large degree of improvement, such as: 32G, 64G u disk. It is portable, it belongs to the mobile storage device, not in the chassis, we can hang it in front of the chest, hanging on the keychain, even in the wallet.
Memory is the channel that connects the CPU and other devices! Play buffer and data exchange Function!
The function of memory and the classification of memory is the main part of the computer, it is relative to the external storage. The programs that we normally use, such as Windows system, typing software, game software, etc., are generally installed in the hard disk, such as external memory, but only this is not the use of its functions, they must be transferred into the RAM to run in order to really use its function, we usually enter a paragraph of text, or play a game, In fact, it's all in memory. Typically, we store a large amount of data that is permanently stored on the external memory, and put some temporary or small amounts of data and programs on the RAM.
Two, memory is divided into DRAM and rom two kinds, the former is also called Dynamic random memory, one of its main characteristics is the loss of data after the power outage, we usually say that the memory refers to this one; the latter is also called read-only memory, we usually boot is stored on the motherboard ROM in the BIOS program, Then it calls the Windows or Linux system on the hard drive, and one of the main features of ROM is that data is not lost after power outages.