Is there a difference between U disk and memory?

There are a lot of newcomers who are not very clear about the concept of U disk and memory. Now, follow the small series to charge and charge. The U disk is the abbreviation of the USB disk, and the USB disk is just the homophonic name of the U disk. A USB flash drive is a type of flash memory, so it is also called a flash drive. The biggest feature is: small and easy to carry, large storage capacity, and inexpensive. It is one of the main mobile storage devices. Now the general U disk capacity is 1G, 2G, 4G, 8G, 16G or larger. The price is the most common 8G, for example, 70 yuan can be bought. U disk capacity has been greatly improved, such as: 32G, 64G U disk. It is easy to carry and is a mobile storage device. It is not plugged into the chassis. We can hang it on the chest, hang it on the keychain, or even put it in the wallet. Memory is the channel that connects the CPU to other devices! It acts as a buffer and data exchange! First, the role of memory and classification of memory is the main component of the computer, it is relative to external storage. The programs we usually use, such as Windows systems, typing software, game software, etc., are generally installed on the external storage such as the hard disk, but only the function can not be used, they must be transferred to the memory to run, in order to truly Using its features, we usually enter a paragraph of text, or play a game, in fact, all in memory. Usually we store a large amount of data to be stored permanently on external storage, and put some temporary or small amount of data and programs in memory. Second, the memory is divided into DRAM and ROM. The former is also called dynamic random access memory. One of its main features is that data will be lost after power off. The memory we usually say refers to this kind; the latter is also called read-only memory. We usually start the BIOS program stored in the ROM on the motherboard, and then call it to the Windows or Linux system on the hard disk. One of the main features of the ROM is that the data will not be lost after power off.