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Computer Glossary



An easy to use glossary of computer and Internet terms with definitions that are easy to understand. Terms and definitions relating to computer, technology, Internet resources and much more.

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What is Hacker?
While this term originally referred to a clever or expert programmer, it is now more commonly used to refer to someone who can gain unauthorized access to other computers. A hacker can "hack" his or her way through the security levels of a computer system or network. This can be as simple as figuring out somebody else's password or as complex as writing a custom program to break another computer's security software. Hackers are the reason software manufacturers release periodic "security updates" to their programs. While it is unlikely that the average person will get "hacked," some large businesses and organizations receive multiple hacking attempts a day.



What is Halftone?
A halftone image is made up of a series of dots rather than a continuous tone. These dots can be different sizes, different colors, and sometimes even different shapes. Larger dots are used to represent darker, more dense areas of the image, while smaller dots are used for lighter areas.



What is Handle?
In online chat, the name you use is often referred to as your screen name, or handle. So if you decided to name yourself MooCow123, that would be your handle. Handles are nice because they allow you to represent yourself without giving away your real identity. The term originated from CB radio, where people refer to each other by their "handles."



What is Hard Disk?
When you save data or install programs on your computer, the information is typically written to your hard disk. The hard disk is a spindle of magnetic disks, called platters, that record and store information. Because the data is stored magnetically, information recorded to the hard disk remains intact after you turn your computer off. This is an important distinction between the hard disk and RAM, or memory, which is reset when the computer's power is turned off.



What is Hard Drive?
The hard drive is what stores all you data. It houses the hard disk, where all your files and folders are physically located. A typical hard drive is only slightly larger than your hand, yet can hold over 100 GB of data. The data is stored on a stack of disks that are mounted inside a solid encasement. These disks spin extremely fast (typically at either 5400 or 7200 RPM) so that data can be accessed immediately from anywhere on the drive. The data is stored on the hard drive magnetically, so it stays on the drive even after the power supply is turned off.



What is HDTV?
Stands for "High Definition Televsion." HDTV is a high-quality video standard developed to replace older video formats often referred to as SDTV (standard definition television). While HDTV's video quality is one of the most noticeable improvements over SDTV, HDTV includes a number of other important improvements as well. First of all, the HDTV signal is digital. Instead of an analog signal, used by traditional NTSC broadcasts, HDTV is always digital. This eliminates analog interference caused be electrical currents and magnetic fields. Secondly, HDTV uses a different aspect ratio than SDTV. While previous broadcasts used a 4:3 ratio (4 units wide for every 3 units tall), HDTV uses a ratio of 16:9. This wider aspect ratio more closely emulates how humans see the world, making the image appear more realistic. This ratio is also better for watching widescreen movies, which are recorded in widescreen for the same reason. True to its name, high definition television offers a much higher resolution than standard definition video. While a typical analog broadcast in the U.S. contains a maximum of 525 horizontal lines of resolution, an HDTV signal supports up to 1080. The three formats used by HDTV are 1080i (interlaced), and 720p and 1080p (progressive). HDTV's higher resolution produces images that are much finer and contain more detail and more color than previous formats. HDTV also provides a higher-quality digital audio signal than SDTV and supports up to six audio channels compared to the two channels allowed previously. To watch HDTV, you need an HDTV-compatible television and a means of receiving an HDTV signal. HDTVs come in both 16:9 and 4:3 formats (for backwards compatibility). Some HDTVs include HDTV tuners for receiving over-the-air broadcasts, but others require the receiver to be bought separately. Fortunately, most cable and satellite TV companies offer HDTV-compatible boxes with their digital service plans.



What is HDV?
Stands for "High-Definition Video." According to a consortium of manufacturers including Sony, JVC, Canon, and Sharp, it is a "consumer high-definition video format." HDV is the next step up from Mini DV, which has been used in consumer digital camcorders for several years. The HDV technology allows high-definition video to be recorded on a Mini DV tape, using MPEG-2 compression. Of course, recording in high-definition requires an HD camcorder, such as the Sony HDR-FX1 or the JVC GR-HD1. These cameras are significantly more expensive than their Mini DV counterparts, but can capture much higher quality video. HDV uses a native 16:9 widescreen format, with a resolution of 1280 x 720 pixels. This is a substantial improvement over Mini DV, which records video in a 4:3 format, with a maximum resolution of 500 horizontal lines. Most HDV camcorders allow the user to record in standard DV as well, but if you shell out a couple thousand dollars extra for a HDV camcorder, you might as well shoot everything in HD.



What is Hexadecimal?
Hexadecimal is a base-16 number system. It is a different method of representing numbers than the base-10 system we use in every day practice. In base-10, we count in multiples of 10 before adding another digit. For example, "8 - 9 - 10 - 11 - 12..." and "98 - 99 - 100 - 101 - 102..." Notice how a new digit is added when the number 10 is reached, and another digit is added to represent 100 (10x10). In base-16, or the hexadecimal number system, each digit can have sixteen values instead of ten. The values of a hexadecimal digit can be: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F Therefore, the number 12 (in the common base-10 format) would be represented as "C" in hexadecimal notation. The number 24 would be 18 (16+8). 100 is 64 in hexadecimal (16x6 + 4) and 1000 is 3E8 (256x3 + 16x14 + 8). While computers process numbers using the base-2, or binary system, it is often more efficient to visually represent the numbers in hexadecimal format. This is because it only takes one hexadecimal digit to represent four binary digits. Since there are eight binary digits in a byte, only two hexadecimal digits are needed to represent one byte.



What is HFS?
Stands for "Hierarchical File System." HFS is the file system used for organizing files on a Macintosh hard disk. When a hard disk is formatted for a Macintosh computer, the hierarchical file system is used to create a directory that can expand as new files and folders are added to the disk. Since HFS is a Macintosh format, Windows computers cannot recognize HFS-formatted drives. Windows hard drives are typically formatted using WIN32 or NTFS file systems.



What is Hit?
Hit is a request for a file on a webserver. Each HTML document and graphic file counts as a separate hit, so they aren't an accurate representation of the number of different visitors to your site.



What is Home Page?
This is the starting point or front page of a Web site. This page usually has some sort of table of contents on it and often describes the purpose of the site. For example, http://www.sharpened.net/index.php is the home page of Sharpened.net. When you type in a basic URL, such as "http://www.cnet.com," you are typically directed to the home page of the Web site. Many people have a "personal home page," which is another way the term "home page" can be used.



What is Host?
This is a computer that acts as a server for other computers on a network. It can be a Web server, an e-mail server, an FTP server, etc. For example, a Web host is what provides the content of Web pages to the computers that access it. A host is also known as the mother computer. Well, not really, I just made that up.



What is Hover?
When you roll the cursor over a link on a Web page, it is often referred to as "hovering" over the link. This is somewhat like when your boss hovers over you at work, but not nearly as uncomfortable. In most cases, the cursor will change from a pointer to a small hand when it is hovering over a link. Web developers can also use cascading style sheets (CSS) to modify the color and style of link when a user hovers over it. For example, the link may become underlined or change color while the cursor is hovering over it.



What is HTML?
HyperText Markup Language (HTML) is a markup language designed for the creation of web pages and other information viewable in a browser.



What is HTTP?
HTTP (HyperText Transfer Protocol) is the primary method used to convey information on the World Wide Web. The original purpose was to provide a way to publish and receive HTML pages.



What is HTTPS?
HTTPS is the secure version of HTTP, the communication protocol of the World Wide Web. It was invented by Netscape Communications Corporation to provide authentication and encrypted communication and is used in electronic commerce.



What is Hub?
This is a hardware device that is used to network multiple computers together. It is a central connection for all the computers in a network, which is usually Ethernet-based. Information sent to the hub can flow to any other computer on the network. If you need to connect more than two computers together, a hub will allow you to do so. If you only need to network two computers together, a simple crossover Ethernet cable will do the trick.



What is Hyper-Threading?
Hyper-threading is a technology developed by Intel Corporation. It is used in certain Pentium 4 processors and all Intel Xeon processors. Hyper-threading technology, commonly referred to as "HT Technology," enables the processor to execute two threads, or sets of instructions, at the same time. Since hyper-threading allows two streams to be executed in parallel, it is almost like having two separate processors working together.



What is Hyperlink?
A hyperlink, or simply a link, is a reference in a hypertext document to another document or other resource. As such it would be similar to a citation in literature. However, combined with a data network and suitable access protocol, it can be used to fetch the resource referenced. This can then be saved, viewed, or displayed as part of the referencing document.



What is Hypertext?
Hypertext is a user interface paradigm for displaying documents which contain automated cross-references to other documents called hyperlinks. Selecting a hyperlink causes the computer to display the linked document within a very short period of time.