To ensure this information isn't stolen as well, having a locked flash drive can keep anyone from viewing your files should the drive fall into the wrong hands. Tiny and portable, they easily slip into a pants or coat pocket, in a computer bag or purse, and come in a variety of shapes and sizes. External keypads add an additional level of security to portable memory, meaning a viewer must first input a numerical code to gain access to files. These in turn can be encrypted and password protected, deterring serious threats to personal security.
Some manufacturers, aiming at a "best of both worlds" solution, have produced card readers that approach the size and form of USB flash drives (e.g., Kingston MobileLite,[65] SanDisk MobileMate[66]) These readers are limited to a specific subset of memory card formats (such as SD, microSD, or Memory Stick), and often completely enclose the card, offering durability and portability approaching, if not quite equal to, that of a flash drive. Although the combined cost of a mini-reader and a memory card is usually slightly higher than a USB flash drive of comparable capacity, the reader + card solution offers additional flexibility of use, and virtually "unlimited" capacity. The ubiquity of SD cards is such that, circa 2011, due to economies of scale, their price is now less than an equivalent-capacity USB flash drive, even with the added cost of a USB SD card reader.
On the more practical side our flash drives, also called thumbdrives or memory sticks are available in memory capacities from 64MB to 256GB. With memory capacities like that, we certainly have the options to cover whatever your data storage requirements may be. For more information on data storage capacities, check out our USB Flash Drive Capacity Guide.
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.
Installers of some operating systems can be stored to a flash drive instead of a CD or DVD, including various Linux distributions, Windows 7 and newer versions, and macOS. In particular, Mac OS X 10.7 is distributed only online, through the Mac App Store, or on flash drives; for a MacBook Air with Boot Camp and no external optical drive, a flash drive can be used to run installation of Windows or Linux.
