What is a flash drive?
Published: Updated:
Short answer
A flash drive (also called a USB flash drive, thumb drive or jump drive) is a small, removable storage device that keeps files in NAND flash memory and plugs into a computer’s USB port. It has no spinning platters. The host sees it as removable media you can copy files to and later eject. Microsoft’s Windows support pages list USB flash drives alongside other external storage when moving files between PCs and when safely removing hardware (Move files with an external storage device, Safely remove hardware).
The USB connectors and protocols themselves are standardised by the USB Implementers Forum (USB-IF), the industry group behind the Universal Serial Bus specifications (USB-IF About).
What is inside
| Piece | Role |
|---|---|
| NAND flash | Non-volatile memory that keeps data without power (same broad technology family as SSDs and SD cards) |
| Controller | Manages reading/writing flash and speaks USB to the host |
| USB plug | Type-A, Type-C or both (via cable) — must match a port your PC actually has |
| Enclosure | Stick / keychain form factor (unlike a 2.5-inch or brick-shaped portable SSD) |
Flash drive vs portable SSD vs internal SSD
| USB flash drive | Portable / external SSD | Internal SSD | |
|---|---|---|---|
| Typical shape | Stick / thumb | Enclosed brick (e.g. Samsung T7 85 × 57 × 8 mm) | 2.5-inch or M.2 inside the PC |
| Host interface | USB | USB (example: USB 3.2 Gen 2 on the T7) or Thunderbolt | SATA or NVMe/PCIe |
| Example rated speed | Varies widely by stick; check that model’s sheet | T7 up to 1,050 / 1,000 MB/s (datasheet) | SATA ~560 MB/s; NVMe much higher — NVMe vs SATA |
| Common job | Move documents, installers, small backups | Large projects, video, full-system images | OS and games |
A portable SSD is still “flash storage over a cable,” but it is sold and warranted as an SSD enclosure with SSD-class controllers — see External SSD vs internal SSD. A flash drive is the stick-class product Windows and camera kits usually mean by “USB flash drive.”
How to use one (Windows)
Microsoft’s guidance for moving files with an external storage device (USB drive, SD card or external hard drive):
- Connect the drive.
- Copy folders via File Explorer (Send to / Copy to the drive).
- Eject before unplugging so files are not corrupted (Microsoft Support).
The same eject step is covered under Safely Remove Hardware — Microsoft explicitly names USB flash drives in that article (Safely remove hardware).
Flash drives are also commonly used as Windows installation media; Microsoft’s install/upgrade documentation refers to USB flash drives for that role (Create installation media).
Names you will see
Thumb drive, jump drive and USB stick are informal synonyms for a USB flash drive. They are not separate standards bodies. What matters for speed is the USB generation the stick and the host port both support (USB 2.0 vs USB 3.x / USB4), plus the stick’s own controller — always read that product’s datasheet rather than assuming every “3.0” stick is equally fast.
FAQ
Is a flash drive an SSD? Both use NAND flash. In everyday PC language an “SSD” is a SATA/NVMe drive (or a portable SSD enclosure). A flash drive is the stick-class USB product. Calling every flash device an SSD is informal.
How do I eject safely? Use Safely Remove Hardware / Eject Media, wait for the safe-to-remove notification, then unplug (Microsoft).
Flash drive vs SD card? SD / microSD are the SD Association’s card form factors (What is an SD card?). A flash drive uses a USB plug instead of an SD slot. Some card readers are themselves USB devices.
Related how-tos
- How to save iPhone photos to a flash drive — steps summarised from Apple Support.
- External SSD vs internal SSD — when a USB SSD is a better fit than a stick.
- What is an SD card? — removable cards versus USB flash.