A scanner is an optional piece of computer hardware that uses reflected light to capture images and translate them into files a computer can read and display. Scanners come in high- and low-resolution versions, and can scan images in either black-and-white or color. The basic functions of a scanner can be adapted to a wide variety of uses, depending on your needs.
One very common use for scanners is copying. If you need to make multiple copies of a flyer, poster, worksheet or similar document and don't have access to a traditional copier, a scanner can be used to create a computer file for your document that can be printed as many times as you need, assuming your computer is hooked up to a printer. Also, unlike a copier, a scanner gives you the option of editing your document before you print your copies.
Another popular use for scanners is digital archiving. Digital archiving is the process of making and saving digital copies of hard copy documents. These documents can include anything from personal documentation and tax paperwork to family letters and business records. Having more than one copy of valuable documents makes the information in said documents that much easier to recover in the event the original documents are lost, stolen or destroyed.
Scanners are also useful for research purposes. Long-term research projects, whether for school or business, will often require information to be gathered from borrowed library books or other privately-owned sources. If the information contained in these sources is necessary for later research, it can be scanned into your computer and referenced at a later date without the need for the original book or document. This allows you to return the source without sacrificing the information found in it.
You can also use scanners to share hard copy photos with friends and family via the Internet. While digital photography has become the prevalent format for professional and amateur photographers alike, many people still have old family photos taken with traditional film cameras and therefore were never recorded digitally. Scanners allow you to create digital copies of these photographs that can be posted to social networking sites like Facebook or emailed directly to distant friends and family.