Yes you can but if you have a lot of files, a flash drive won't back it all up. If you only need to back up 32GB-64GB for example, you could back it up on the flash drive. However, anything bigger isn't sensible for flash drives; you're better off getting an external hard drive. Also, it's not a long-term storage option––it can corrupt easily or be lost.
The various writable and re-writable forms of CD and DVD are portable storage media supported by the vast majority of computers as of 2008. CD-R, DVD-R, and DVD+R can be written to only once, RW varieties up to about 1,000 erase/write cycles, while modern NAND-based flash drives often last for 500,000 or more erase/write cycles. DVD-RAM discs are the most suitable optical discs for data storage involving much rewriting.
“The transfer speeds are satisfyingly fast for reading and writing all kinds of files, whether large HD videos or unsorted media folders,” our tester reported of this flash drive. He also liked the inclusion of the SecureAccess file encryption, although advanced features are an additional purchase. In terms of negatives, our reviewer called the plastic shell casing “flimsy and fragile” and observed that the transfer speeds are capped when the flash drive is plugged into a USB hub. Overall? Our tester was “more than satisfied with the transfer speeds, but would have appreciated a better, sturdier physical design.”
Many companies make small solid-state digital audio players, essentially producing flash drives with sound output and a simple user interface. Examples include the Creative MuVo, Philips GoGear and the first generation iPod shuffle. Some of these players are true USB flash drives as well as music players; others do not support general-purpose data storage. Other applications requiring storage, such as digital voice or sound recording, can also be combined with flash drive functionality.[57]

Yes you can but if you have a lot of files, a flash drive won't back it all up. If you only need to back up 32GB-64GB for example, you could back it up on the flash drive. However, anything bigger isn't sensible for flash drives; you're better off getting an external hard drive. Also, it's not a long-term storage option––it can corrupt easily or be lost.

Not everyone wants every file they've ever created available in the cloud. It can put data at risk - not just from hackers or spammers or nosey bosses, but with some providers offering shady terms, you could lose the intellectual rights to anything uploaded. Having a portable memory drive means you don't have to sacrifice mobility for security, though, making flash drives an ideal solution for business people on the go.
With their paper-slim profiles, Ultrabooks and tablets are barely thick enough for a USB port. That's why some of the bulkier drives on this list are not ideal for those devices. Meanwhile, Samsung’s Fit drives are slim and compact, about the size of your thumb nail. This unobtrusive storage is constructed with a metal casing that is resistant to the elements and NAND flash technology. With USB 3.0 tech you can expect fast read speeds, while the price is easy to stomach. Just make sure to attach it to a lanyard, so you don't lose it.
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]

M-Systems, an Israeli company, were granted a US patent on November 14, 2000, titled "Architecture for a [USB]-based Flash Disk", and crediting the invention to Amir Ban, Dov Moran and Oron Ogdan, all M-Systems employees at the time. The patent application was filed by M-Systems in April 1999.[6][1][7] Later in 1999, IBM filed an invention disclosure by one of its employees.[1] Flash drives were sold initially by Trek 2000 International, a company in Singapore, which began selling in early 2000. IBM became the first to sell USB flash drives in the United States in 2000.[1] The initial storage capacity of a flash drive was 8 MB.[7] Another version of the flash drive, described as a pen drive, was also developed. Pua Khein-Seng from Malaysia has been credited with this invention.[8] Patent disputes have arisen over the years, with competing companies including Singaporean company Trek Technology and Chinese company Netac Technology, attempting to enforce their patents.[9] Trek won a suit in Singapore,[10][11] but has lost battles in other countries.[12] Netac Technology has brought lawsuits against PNY Technologies,[13] Lenovo,[14] aigo,[15] Sony,[16][17][18] and Taiwan's Acer and Tai Guen Enterprise Co.[18]

Floppy disk drives are rarely fitted to modern computers and are obsolete for normal purposes, although internal and external drives can be fitted if required. Floppy disks may be the method of choice for transferring data to and from very old computers without USB or booting from floppy disks, and so they are sometimes used to change the firmware on, for example, BIOS chips. Devices with removable storage like older Yamaha music keyboards are also dependent on floppy disks, which require computers to process them. Newer devices are built with USB flash drive support.
Buoyed by its rocket-like speeds, the Extreme Go lives up to its name by transferring a 4K movie in less than 40 seconds — that's nearly 35 times the speed of a USB 2.0 drive and thanks to USB 3.1 hardware. Beyond its fast operation, the Sandisk looks as good as it performs with a sleek and slim package that's 2.79 x 0.84 x 0.45 inches in size and weighs only 4.8 ounces. The retractable connector makes it easy to store when not in use and it is backward compatible with any USB 3.0 or USB 2.0 port. Tucked inside its diminutive profile is a choice of 64GB or 128GB of storage capacity and it comes complete with data storage recovery in the event of an accidental file deletion. 
Counterfeit USB flash drives are sometimes sold with claims of having higher capacities than they actually have. These are typically low capacity USB drives which are modified so that they emulate larger capacity drives (for example, a 2 GB drive being marketed as a 64 GB drive). When plugged into a computer, they report themselves as being the larger capacity they were sold as, but when data is written to them, either the write fails, the drive freezes up, or it overwrites existing data. Software tools exist to check and detect fake USB drives,[43][44] and in some cases it is possible to repair these devices to remove the false capacity information and use its real storage limit.[45]
Modern devices are thinner and lighter, and the Type-C connector is a plug format designed to work with these products. In addition to being smaller than a standard USB plug, Type-C connectors are reversible, so they're easier to use. Some USB flash drives include both a traditional plug and a Type-C connector. These products are ideal for transferring files between computers and portable devices such as smartphones or tablets.