Computer Terms Beginning with "E"

[MysteRy]

Exbibyte

A exbibyte is a unit of data storage that equals 2 to the 60th power, or 1,152,921,504,606,846,976 bytes.

While a exabyte can be estimated as 10^18 or 1,000,000,000,000,000,000 bytes, a exbibyte is exactly 1,152,921,504,606,846,976 bytes. This is to avoid the ambiguity associated with the size of exabytes. A exbibyte is 1,024 pebibytes and precedes the zebibyte unit of measurement.

[MysteRy]

Excel

Microsoft Excel is a spreadsheet program for Windows and Macintosh computers. It is part of the Microsoft Office suite, which includes other productivity programs, such as Word and PowerPoint.

Though Excel is developed by Microsoft, the first version of the program was released for the Macintosh in 1985. It wasn't until 1987, when Microsoft introduced Windows 3.0, that Excel was made available for Windows. Since then, Microsoft has supported the program on both platforms, releasing updates about every two years.

Some other popular spreadsheet programs include IBM Lotus 1-2-3 (for Windows) and the AppleWorks spreadsheet program (for the Mac). However, Microsoft Excel has led the spreadsheet market for many years and continues to be the most popular spreadsheet program for both businesses and consumers.

[MysteRy]

Expansion Card

An expansion card is a printed circuit board that can be installed in computer to add functionality to it. For example, a user may add a new graphics card to his computer to give it more 3D graphics processing power. An audio engineer may add a professional sound card to his machine to increase the computer's audio input and output connections. Users that need more Firewire or USB ports can add Firewire or USB expansion cards, which provide additional connections.

Most expansion cards are installed in PCI slots. This includes variations of PCI, such as PCI-X and PCI Express. Graphics cards may also be installed in an AGP slot, which is designed specifically for video cards. Since expansion cards require open slots, they can only be installed in computers that have available expansion slots. Therefore, computers like the Apple iMac and other all-in-one machines cannot accept expansion cards. Computer towers, however, often have two or three open expansion slots, and can accept multiple cards.

Laptops don't use traditional expansion cards because of their small form factor. However, some models can accept removable PCMCIA cards that add extra ports or other functionality to the computer.

[MysteRy]

External Hard Drive

Nearly all personal computers come with an internal hard drive. This drive stores the computer's operating system, programs, and other files. For most users, the internal hard drive provides enough disk space to store all the programs and files. However, if the internal hard drive becomes full or if the user wants to back up the data on the internal hard drive, and external hard drive may be useful.

External hard drives typically have one of two interfaces - USB or Firewire. USB hard drives commonly use the USB 2.0 interface because it supports data transfer rates of up to 480 Mbps. USB 1.1 only supports transfers of up to 12 Mbps, which would make the hard drive seem slow to even the most patient people. Firewire drives may use either Firewire 400 or Firewire 800, which support data transfer rates of up to 400 and 800 Mbps respectively.

The most likely users to need external hard drives are those who do audio and video editing. This is because high-quality media files can fill up even the largest hard drives. Fortunately, external hard drives can be daisy chained, which means they can be connected one after the other and be used at the same time. This allows for virtually unlimited amounts storage.

Users who do not require extra storage may still find external hard drives useful for backing up their main hard drive. External hard drives are a great backup solution because they can store an exact copy of another hard drive and can be stored in a safe location. Using the drive to restore data or perform another backup is as simple as connecting it to the computer and dragging the necessary files from one drive to another.

While most external hard drives come in heavy, protective cases, some hard drives are designed primarily for portability. These drives usually don't hold as much data as their larger desktop counterparts, but they have a sleek form factor and can easily be transported with a laptop computer. Some portable drives also include security features such as fingerprint recognition that prevent other people from accessing data on the drive in case it is lost.

[MysteRy]

Extranet

If you know the difference between the Internet and an intranet, you have an above average understanding of computer terminology. If you know what an extranet is, you may be in the top echelon.

An extranet actually combines both the Internet and an intranet. It extends an intranet, or internal network, to other users over the Internet. Most extranets can be accessed via a Web interface using a Web browser. Since secure or confidential information is often accessible within an intranet, extranets typically require authentication for users to access them.

Extranets are often used by companies that need to share selective information with other businesses or individuals. For example, a supplier may use an extranet to provide inventory data to certain clients, while not making the information available to the general public. The extranet may also include a secure means of communication for the company and its clients, such as a support ticket system or Web-based forum.

Unlike the Internet, "extranet" is not a proper noun and therefore should not be capitalized.