38. What is a scanner? How does it work ?What do you think are the benefits of using scanners in business?

A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. Scanners come in hand-held, feed-in, and flatbed types and for scanning black-and-white only, or color. Very high resolution scanners are used for scanning for high-resolution printing, but lower resolution scanners are adequate for capturing images for computer display. Scanners usually come with software, such as Adobe's Photoshop product, that lets you resize and otherwise modify a captured image.

Scanners usually attach to your personal computer with a Small Computer System Interface ( SCSI ). An application such as PhotoShop uses the TWAIN program to read in the image.

Some major manufacturers of scanners include: Epson, Hewlett-Packard, Microtek, and Relisys.

A scanner is used to scan in printed photographs and other documents so they

can be put into documents or web pages. It uses a light source,

typically a cold cathode lamp to illuminate the scanned imaged. The

light is then reflected off the object and into Charged Coupled Device

(CCD). The Charged Coupled Device collects the information, and through

a series of electronic devices converts the analog signal into a series

of digital signals which can then be read and processed by the internal

electronics of the scanner and subsequently a computer.

A flatbed scanner is best for people who need to copy photographs in high resolution or convert documents into image files. They are useful for reproducing images. They can also save storage space, since the original document can sometimes be discarded after it's been scanned. Sheet-fed scanners can read multiple sheets very quickly and can be used to fax documents. All-in-one scanners are very convenient, since they combine multiple functions into a small device. They are best for home and small business users who need to scan, fax, copy or print just a few documents at a time. Handheld scanners such as bar code and pen scanners can quickly read data from products, invoices and packing slips.

39. What is a printer? How does a laser printer work? What do you think are the benefits of using laser printers in business?

A computer printer is a computer peripheral device that produces a hard copy (permanent human-readable text and/or graphics, usually on paper) from data stored in a computer connected to it A printer is used to print anything that you want, like pictures or documents or data. Printers are awesome devices that plug in where there is a USB slot, from there you can click print and the document is sent to the port where you document is printed onto a piece of paper. You can print images, documents, cards, etc.

A laser printer is so-called because a laser beam is essential in its operations. It is also distinct from other printers because of its great printing speeds as well as highly accurate rendering. For instance, there are laser printers in the market that can print a hundred colored pages and two hundred non-colored pages every minute

The laser printer usually requires maintenance after printing about fifty thousand pages (varies from printer to printer). The distinctive procedure for maintenance is to vacuum the entire assembly, and wash or change the paper managing rollers. The rollers are encompassed into a fat rubber covering, which ultimately deteriorate and is covered with oily paper dirt. They can typically be cleansed with a moisture lint-free cloth or chemical liquids that can assist in restoring the grip of the rubber covering. The fuser heating rollers require oil replacement or refilling after few hundred thousand printed pages. The laser printer as compared to other types of printers is quite expensive with more internal components, hence it requires regular maintenance.

1- By using toner laser printer work efficiently than an inkjet. Certainly, a toner can print many more copies than ink cartridges from an inkjet. In the long run, toner is much less expensive than ink, if you factor in the number of pages printed.

2 - Do you need a printer that can make copies fast as possible? If you do then you should consider a laser printer since it has more speed than an ink jet printer. When time is the primary factor, you certainly wouldn't want to use an inkjet.

3 - Laser printers have a tendency to be more durable. Their design is much more aesthetic and futuristic. This is allows the printer to work for a long time than an inkjet. Really, would you want to purchase a printer only to see it break down or die out after only a few months? Purchasing a laser printer might prove to be the better option in this regard as it will certainly help you curtail your costs

4 - Quality of image is the most important benifit for buying a laser printer. The detail in the text and photos that are produced by a laser printer are generally of the highest quality. Forget about imperfections such as streaks, smears, and filminess. Choose a laser printer over an inkjet, if the quality of the images produced is your first matter of concern.

5 - Inject cartridges may leak due to problem in installation. If you buy a laser printer, you won't have to worry about ink leaking from the cartridge and thereby causing damage to your printer.

6 - Inkjet printers aren't as good for using at a business as laser printers are. Using a laser printer can help avoid many potential problems.

7 - Plus, it goes without saying that the same advantages that accrue to your business will also be there if you're a serious home user.

40. What is the graphical user interface?

A GUI (usually pronounced GOO-ee) is a graphical (rather than purely textual) user interface to a computer. As you read this, you are looking at the GUI or graphical user interface of your particular Web browser. The term came into existence because the first interactive user interfaces to computers were not graphical; they were text-and-keyboard oriented and usually consisted of commands you had to remember and computer responses that were infamously brief. The command interface of the DOS operating system (which you can still get to from your Windows operating system) is an example of the typical user-computer interface before GUIs arrived. An intermediate step in user interfaces between the command line interface and the GUI was the non-graphical menu-based interface, which let you interact by using a mouse rather than by having to type in keyboard commands.