_{Unlike solid-state memory, hard drives are susceptible to damage by shock (e.g., a short fall) and vibration, have limitations on use at high altitude, and although they are shielded by their casings, they are vulnerable when exposed to strong magnetic fields. In terms of overall mass, hard drives are usually larger and heavier than flash drives; however, hard disks sometimes weigh less per unit of storage. Like flash drives, hard disks also suffer from file fragmentation, which can reduce access speed.}
Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as "180X" (180 times 150 KiB/s).[19] File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30 MB/s and write at about half that rate, which was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB 1.1, which is limited to 12 Mbit/s (1.5 MB/s) with accounted overhead.[20] The effective transfer rate of a device is significantly affected by the data access pattern.[21]

Audio tape cassettes and high-capacity floppy disks (e.g., Imation SuperDisk), and other forms of drives with removable magnetic media, such as the Iomega Zip and Jaz drives, are now largely obsolete and rarely used. There are products in today's market that will emulate these legacy drives for both tape and disk (SCSI1/SCSI2, SASI, Magneto optic, Ricoh ZIP, Jaz, IBM3590/ Fujitsu 3490E and Bernoulli for example) in state-of-the-art Compact Flash storage devices – CF2SCSI.

^{A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal, or rubberized case, which can be carried in a pocket or on a key chain, for example. The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected. Most flash drives use a standard type-A USB connection allowing connection with a port on a personal computer, but drives for other interfaces also exist. USB flash drives draw power from the computer via the USB connection. Some devices combine the functionality of a portable media player with USB flash storage; they require a battery only when used to play music on the go.
USB flash drives have been integrated into other commonly carried items, such as watches, pens, and even the Swiss Army Knife; others have been fitted with novelty cases such as toy cars or Lego bricks. USB flash drives with images of dragons, cats or aliens are very popular in Asia.[36] The small size, robustness and cheapness of USB flash drives make them an increasingly popular peripheral for case modding.}
Like all flash memory devices, flash drives can sustain only a limited number of write and erase cycles before the drive fails.[71][unreliable source?][72] This should be a consideration when using a flash drive to run application software or an operating system. To address this, as well as space limitations, some developers have produced special versions of operating systems (such as Linux in Live USB)[73] or commonplace applications (such as Mozilla Firefox) designed to run from flash drives. These are typically optimized for size and configured to place temporary or intermediate files in the computer's main RAM rather than store them temporarily on the flash drive.
The memory in flash drives is commonly engineered with multi-level cell (MLC) based memory that is good for around 3,000-5,000 program-erase cycles,[40] but some flash drives have single-level cell (SLC) based memory that is good for around 100,000 writes. There is virtually no limit to the number of reads from such flash memory, so a well-worn USB drive may be write-protected to help ensure the life of individual cells.
Also, HP has introduced a USB floppy drive key, which is an ordinary USB flash drive with additional possilibility for performing floppy drive emulation, allowing its usage for updating system firmware where direct usage of USB flash drives is not supported. Desired mode of operation (either regular USB mass storage device or of floppy drive emulation) is made selectable by a sliding switch on the device's housing.[51][52]
We offer the most reliable and consistently top performing customizable, no minimum USB flash drives out there. With more than 25 styles and over 550 different looks, our drives are available in 4GB, 8GB, 16GB, 32GB, 64GB, and 128GB capacities–with most available in USB 3.0 from 16GB and up. We’re so confident in the quality of our drives, each one includes a lifetime warranty.
_{Some organizations forbid the use of flash drives, and some computers are configured to disable the mounting of USB mass storage devices by users other than administrators; others use third-party software to control USB usage. The use of software allows the administrator to not only provide a USB lock but also control the use of CD-RW, SD cards and other memory devices. This enables companies with policies forbidding the use of USB flash drives in the workplace to enforce these policies. In a lower-tech security solution, some organizations disconnect USB ports inside the computer or fill the USB sockets with epoxy.}
Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).[citation needed] Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory. Drives typically use the USB mass storage device class to communicate with the host.[28]
_{Some file systems are designed to distribute usage over an entire memory device without concentrating usage on any part (e.g., for a directory) to prolong the life of simple flash memory devices. Some USB flash drives have this 'wear leveling' feature built into the software controller to prolong device life, while others do not, so it is not necessarily helpful to install one of these file systems.[39]}
A USB flash drive, also commonly known as a thumb drive or a memory stick, is a type of portable data storage device that fits directly into a USB port. It can back up, store, and transfer important data and make that data available to other devices with USB ports. USB drives tend to favor speed and convenience over absolute storage space; discover the wide selection available on eBay.
^{The applications of current data tape cartridges hardly overlap those of flash drives: on tape, cost per gigabyte is very low for large volumes, but the individual drives and media are expensive. Media have a very high capacity and very fast transfer speeds, but store data sequentially and are very slow for random access of data. While disk-based backup is now the primary medium of choice for most companies, tape backup is still popular for taking data off-site for worst-case scenarios and for very large volumes (more than a few hundreds of TB). See LTO tapes.}
Usually, such drives will be custom-stamped with a company's logo, as a form of advertising. The drive may be blank, or preloaded with graphics, documentation, web links, Flash animation or other multimedia, and free or demonstration software. Some preloaded drives are read-only, while others are configured with both read-only and user-writable segments. Such dual-partition drives are more expensive.[61]
Macbooks require a USB Type-C device, which is where this swivel dual flash drive from Silicon Power comes in handy. It features a dual interface with USB Type-C and USB Type-A 3.0 ports on opposite ends of a compact device. The 360-degree swivel cap protects whichever connector is not in use and attaches easily to keychains. The C80 doesn’t require any special drivers or software to work; just plug it into the port and it is ready to go. But it has an optional file management app, which is a free and simple automatic file categorization that puts your work in the appropriate folders. Expect fast read and write speeds and 64 GB of storage to hold all your photos and files.
With wide deployment(s) of flash drives being used in various environments (secured or otherwise), the issue of data and information security remains important. The use of biometrics and encryption is becoming the norm with the need for increased security for data; on-the-fly encryption systems are particularly useful in this regard, as they can transparently encrypt large amounts of data. In some cases a secure USB drive may use a hardware-based encryption mechanism that uses a hardware module instead of software for strongly encrypting data. IEEE 1667 is an attempt to create a generic authentication platform for USB drives. It is supported in Windows 7 and Windows Vista (Service Pack 2 with a hotfix).[47]

It's never been easier to take all the files, data or media you want with you wherever you go. Generally about the size of a stick of gum, a USB flash drive lets you store any file from your computer so you can save it, transport it, and load it onto another computer in seconds. You simply plug the flash drive into your USB port and drag any files you want onto its icon on your desktop. Best of all, flash drives have no internal moving parts, so they're very resistant to breaking by being bumped or dropped.