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.
_{The advent of USB 3.0 makes data transfers over ten times faster than USB 2.0. If you have USB 3.0 port on your device, and you transfer files on a regular basis, the added speed on the PNY flash drive can be a big boost for getting things done (Even if you have a USB 2.0 port, you can still use USB 3.0, but you won’t get the same speeds). Pros: Fastest file transfers of any of the options. Cons: Some found the built-in external cover difficult to move. Image Courtesy of Amazon}

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.

In addition to providing reliable storage for information, many of these products come with security software that protects your personal data if you lose your device. The software secures files with 128-bit AES encryption and requires a password to unlock the stored information. It also features a drag-and-drop user interface that simplifies transferring and securing your data.
"Helps transfer data without bulky external drives....Compared to the Ultra Flash Drives I purchased (which are designed for faster downloads), this Flash Drive took just a little bit longer for downloading a large quantity of items, but it really was not that much of a time difference, so I am extremely satisfied with the speed and abilities of the Cruzer"
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.
Universal Serial Bus (USB) is a standard that defines both communication protocols and physical connections for data transfer. Using thumb drives based on this standard ensures they work with a broad range of devices, making it simple to show digital pictures on a USB-enabled television, transfer files between Apple and Microsoft computers or use your saved game on a friend's gaming console. These devices also offer plug-and-play compatibility with most operating systems and require no additional software to access the storage they provide.
Universal Disk Format (UDF) version 1.50 and above has facilities to support rewritable discs like sparing tables and virtual allocation tables, spreading usage over the entire surface of a disc and maximising life, but many older operating systems do not support this format. Packet-writing utilities such as DirectCD and InCD are available but produce discs that are not universally readable (although based on the UDF standard). The Mount Rainier standard addresses this shortcoming in CD-RW media by running the older file systems on top of it and performing defect management for those standards, but it requires support from both the CD/DVD burner and the operating system. Many drives made today do not support Mount Rainier, and many older operating systems such as Windows XP and below, and Linux kernels older than 2.6.2, do not support it (later versions do). Essentially CDs/DVDs are a good way to record a great deal of information cheaply and have the advantage of being readable by most standalone players, but they are poor at making ongoing small changes to a large collection of information. Flash drives' ability to do this is their major advantage over optical media.
A drawback to the small size of flash drives is that they are easily misplaced or otherwise lost. This is a particular problem if they contain sensitive data (see data security). As a consequence, some manufacturers have added encryption hardware to their drives, although software encryption systems which can be used in conjunction with any mass storage medium will achieve the same result. Most drives can be attached to keychains or lanyards. The USB plug is usually retractable or fitted with a removable protective cap.
USB flash drives are portable and easy-to-use data storage devices. They're compatible with desktop computers and laptop computers as well as a broad range of game consoles and media devices. Use them to transfer data between systems, share files with friends and colleagues or create backups of critical information. Staples offers a complete selection of high-capacity thumb drives, including popular brands such as Lexar, PNY, Samsung, SanDisk and Verbatim.