《计算机英语》课件Chapter 5 Secondary Storage

1、? ?计算机英语计算机英语? ?课件课件Chapter 5 Secondary Chapter 5 Secondary StorageStorageChapter 5 Secondary StorageObjectiveAfter reading this chapter, you should be able to: lDistinguish the difference between Primary storage and Secondary storage.lExplain what functions that secondary storage devices perform in

2、 the computer system.lComprehend the characteristics of common secondary storage devices.5.1 Secondary StoragelSecondary storage (or secondary memory) is where programs and data are kept on a long-term basis. lThe three types of secondary storage: hard disks, optical disks, and USB flash drives. 5.2

3、 Hard DiskslA hard disk is one of the most important components within the PC. It is a device where you permanently store programs and data. Figure 5-1 Hard disk: Opened hard drive with top magnet removed Platter Spindle Head 5.3 Optical DiskslAn optical disc is a flat, circular disc wherein data is

4、 stored in the pits (or bumps) in its flat surface sequentially on the continuous, spiral track extending from the innermost track to the outermost track, covering the entire disc surface. lThere are three basic types of optical disks: CD-ROM.CD-R. CD-RW. 5.3 Optical Disks Figure 5-2 Optical disks 5

5、.4 USB Flash DriveslA USB flash drive consists of a NAND-type flash memory data storage device integrated with a USB interface. Figure 5-3 A 16 GB USB flash drive 5.4 USB Flash DriveslUSB flash drives offer potential advantages over other portable storage devices, particularly the floppy disk. They have a more compact shape, operate faster, hold much more data, have a more durable design, and operate more reliably due to their lack of moving parts. 5.5 Solid-state disklAn SSD (solid-state disk) is a storage device that stores persistent data on solid-state flash memory.