USB mass storage device class
The USB mass storage device class is a set of computing communications protocols, specifically a USB Device Class, defined by the USB Implementers Forum that makes a USB device accessible to a host computing device and enables file transfers between the host and the USB device. To a host, the USB device acts as an external hard drive; the protocol set interfaces with a number of storage devices.
USB flash drives typically implement the USB mass storage device class.
An action camera being accessed via mass storage device class
Universal Serial Bus (USB) is an industry standard that allows data exchange and delivery of power between many types of electronics. It specifies its architecture, in particular its physical interface, and communication protocols for data transfer and power delivery to and from hosts, such as personal computers, to and from peripheral devices, e.g. displays, keyboards, and mass storage devices, and to and from intermediate hubs, which multiply the number of a host's ports.
Various legacy USB and related connectors (left to right): USB Micro-B plug, proprietary UC-E6 plug, USB Mini-B plug, Standard-A-like receptacle (non-compliant), Standard-A plug, Standard-B plug. Shown with a centimeter ruler.
USB logo on the head of a standard Type-A (Standard-A) plug
A USB 2.0 PCI expansion card
USB 3.2 Gen 1(x1), Standard-A connectors labelled as USB 3.1 Gen 1 – originally simply named USB 3.0 and marketed as SuperSpeed USB (by USB 3.0 specification) and later named as USB 3.2 Gen 1x1 and marketed as SuperSpeed USB 5Gbps by the USB 3.2 specification