Because optical disks have been basically eliminated now, everyone likes to use USB flash drives to store data. Compared with USB flash drive, CD was eliminated mainly because of its large size and inconvenient carrying. In the past, it had to be packed with CDs. In addition, the CD-ROM drive is easy to scratch the disk surface when used for a long time, causing file damage and making it difficult for the CD-ROM drive to read the disk. Moreover, the CD-ROM drive is easy to deform and has a small capacity, which is far less convenient to use than the U disk.