usb is which type of storage device
Secondary storage refers to storage devices and media that are not constantly accessible by a computer system. Examples include external hard drives, portable flash drives, CDs, and DVDs. These devices and media must be either plugged in or inserted into a computer in order to be accessed by the system.
USB, short for Universal Serial Bus, is an industry standard initially developed in the mid-1990s that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices.It is currently developed by the USB Implementers Forum (USB IF).