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.
Half-Duplex:
Half-duplex is a type of communication in which data can flow back and forth between two devices, but not simultaneously. Each device in a half-duplex system can send and receive data, but only one device can transmit at a time. An example of a half-duplex device is a CB (citizens band) radio. The CB protocol, which is used by truckers, police officers, and other mobile personnel, allows users to communicate back and forth on a specific radio frequency. However, since the CB protocol only supports half-duplex communication, only person can speak at a time. This is why people communicating over two-way radios often say "over" at the end of each statement. It is a simple way of telling the recipient he or she can respond if necessary.

Hard Copy:
A hard copy is a printed document. It may be a text file, photograph, drawing, or any other type of printable file. For example, instead of e-mailing a business memo, it may be sent out as a hard copy, or an actual physical paper containing the memo.
When a document is created on a computer, it is typically saved as a file on the the computer's hard drive. This is sometimes referred to as a soft copy. While the file can be easily opened and edited on a computer, it can also be easily deleted. Therefore, sometimes printing a hard copy is done to create a physical backup of the document.
HDD-The mechanism that controls the positioning, reading, and writing of the hard disk, which furnishes the largest amount of data storage for the PC.
HDMI: Stands for "High-Definition Multimedia Interface." HDMI is a digital interface for transmitting audio and video data in a single cable. It is supported by most HDTVs and related components, such as DVD and Blu-ray players, cable boxes, and video game systems. Because HDMI is a digital connection, HDMI cables are less prone to interference and signal noise than analog cables. Also, since most components, such as DVD players and digital cable boxes process information digitally, using HDMI eliminates the analog to digital conversion other interfaces require. Therefore, HDMI often produces the best quality picture and sound compared to other types of connections.

Heat Sink- dissipates the heat from the processor, preventing it from overheating. The heat sink is made out of metal, such as a zinc or copper alloy, and is attached to the processor with a thermal material that draws the heat from away the processor towards the heat sink.
HTML- Stands for "Hyper-Text Markup Language." This is the language that Web pages are written in. Also known as hypertext documents, Web pages must conform to the rules of HTML in order to be displayed correctly in a Web browser. The HTML syntax is based on a list of tags that describe the page's format and what is displayed on the Web page.

HTTP:
HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web.

Hyperlink:

A hyperlink is a word, phrase, or image that you can click on to jump to a new document or a new section within the current document. Hyperlinks are found in nearly all Web pages, allowing users to click their way from page to page. Text hyperlinks are often blue and underlined, but don't have to be. When you move the cursor over a hyperlink, whether it is text or an image, the arrow should change to a small hand pointing at the link. When you click it, a new page or place in the current page will open.