review_CITA_110_v2.doc

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American University in Bosnia and Herzegovina

CITA 110

Information Technology Terminology Review Document

A Note to Students

This review document is in no way complete. New terms are constantly added in the Information Technology field. If there is a term you do not understand, always search for the term in a dictionary and on the Web. Remember that some words will have both a technical and a non-technical meaning.

Hardware Terminology

CPU – Central Processing Unit, also known as microprocessor. The CPU is a component of a computer that computes or performs instructions.

RAM – Random Access Memory, also known as memory. RAM is a subsystem of a computer used for storing programs and data while they execute. RAM is volatile storage. If a person pulls the plug from a computer, the data stored in RAM is lost.

Hard Disk – a high-capacity, persistent, peripheral storage device. The hard disk, also known as Hard Drive, is non-volatile storage. If a person pulls the plug from a computer, the data on the hard disk is preserved.

Motherboard – contains the processor chip, memory, hard disk, and other computer electronics.

Monitor – a computer’s video output device or display, also known as a screen. Modern monitors are bit-mapped, meaning that they display information stored in the bits of the computer’s memory. Pixels, or picture elements, form a grid on the monitor. The computer displays the information of the screen by drawing each pixel in the color designated for the figure or image. The refresh rate is the frequency with which a video display is redisplayed.

Daughter Board – a small printed circuit board plugged into a motherboard to provide additional functionality. Daughter boards are often called daughter cards or just cards. Networking cards and video cards are examples of daughter boards.

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Operating System Terminology

Window – an area of a computer screen that displays its own file or message independent of the rest of the screen.

Registry – The registry is the repository in Windows Operating Systems responsible for storing configuration settings. A repository is simply storage area for something.

File Structure – the directories and files of a computer.

Networking and Data Communications Terminology

Synchronous Communication – requires that the sender and the receiver are active at the same time. A telephone conversation is an example of synchronous communication.

Asynchronous Communication – sending and receiving occur at different times. A postcard is an example of an asynchronous communication.

Broadcast communication – is when a single sender transmits to many receivers. Radio and television are examples of broadcast communication. The intended audience is the entire population in the signal range.

Multicast communication – is when a single sender transmits to many receivers, but the intended recipients are not the whole population. Magazines are an example of multicast communication.

Point-to-point communication – is when a single sender transmits to a single receiver. Telephone communication is point to point.

Spamming – spam is unsolicited email. In short, spam is email that no one asked for and no one wanted.

Client/Server – a relationship between two computers in which the client computer requests services from the server computer. Most of the interactions over the Internet use client/server protocols.

IP Address – Each computer connected to the Internet is given a unique address called its IP Address, short for Internet Protocol Address. IP addresses have the following format: 172.17.12.230.

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DNS – The Domain Name System translates the hierarchical, human-readable names into the numeric IP addresses they represent.

DNS Server – a Domain Name System server maintains a list of DNS Names with their corresponding IP addresses. Every computer or host on the Internet knows the IP address of its nearest DNS Server. When you type, http://www.cnn.com, into your web browser, your computer asks your local DNS server for the IP address associated with this DNS Name.

Root Name Server – a top-level DNS server that maintains the master list of all of the name-to-address translations. If the Root Name Server does not know, the query is forwarded to the Authoritative Name Server.

Authoritative Name Server – a DNS Server that maintains a record of the name-to-address translations for its domain.

Top-level Domains – the final part of a domain name that represents the broad category of the institution sponsoring the name. For example, .edu is the top-level domain for educational institutions. Recently, the rules for top-level domains have changed allowing virtually any top-level domain desired.

TCP/IP – Transmission Control Protocol/Internet Protocol is the protocol suite that allows computers to communicate over the Internet.

WAN – Wide area networks are networks that connect computers over a wider area than a few kilometers.

LAN – Local area networks are networks that connect computers within a small physical space such as a building. Ethernet is the main technology for local area networks.

HTTP – Hypertext Transfer Protocol is the protocol a web browser uses to communicate with a web server.

HTML – Hypertext Markup Language is the programming language interpreted by web browsers. HTML commands are called tags. The example below demonstrates well-formed HTML tags.

<title>Kelly Clarkson – In Concert</title> </head>

<body>

<h1>Kelly Clarkson! Live!</h1> </body>

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HTML Command Review

Command Purpose Example

<html> Defines beginning of HTML document

</html> Defines end of HTML document <head>

</head>

Defines the header information of the document

<title>Title of Page</title> </head>

…. <body>

</body>

Defines the body or main part of the document.

<title>Title of Page</title> </head>

<body>

<h1>Title of Page</h1> </body>

</html>  HTML comment. The text in this

tag will NOT be displayed on the page. Programmers use HTML comments to organize documents.

<h1></h1> Heading 1. Large heading that defines a section of a document.

<body>

<h1>Title of Page</h1> </body>

Heading 2 and 3. Smaller

headings that defines subsections of a document.

<body>

<h1>Title of Page</h1> <h2>Chapter 1</h2> <h2>Chapter 2</h2> <h3>Section 2A</h3> <h3>Section 2B</h3> <h2>Chapter 3</h2> </body>

<hr /> Horizontal Rule creates a horizontal line on the web page. <br /> Line break creates a line break

and carriage return on the page.

<b></b> Bold tag <b>Bold Text</b> <i></i> Italic tag <i>Italic Text</i> <u></u> Underline tag <u>Underline Text</u> <p></p> Paragraph tag formats text as a

block of text.

<p>This text is an example of a paragraph.</p>

<ul></ul> Unordered list tag produces bullet points.

<ul>

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<li>Lizard</li> </ul>

<ol></ol> Ordered list tag produces a list as

a sequence of numbers. <ol> <li>Wake up</li> <li>Eat breakfast</li> <li>Study for exam</li> </ol>

The font tag formats the style, size, and color of text.

<a></a> The anchor tag creates links from one page to another.

Additional Notes concerning HTML

HTML tags have attributes. The correct structure of an attribute is as follows:

Where bgcolor is the name of the attribute and Blue is the value of the attribute. The name and the value are always separated by and equals (=) sign. The value is usually placed inside quotation marks (“).

RSA – The public key/private key encryption algorithm that makes HTTPS technology work. RSA stands for the people who invented the technology: Rivest, Shamir, and Adelman.

Encryption – the transformation of a digital representation so that the information in the representation is hidden. Data that is not encrypted is called clear text.

General Computing Terminology

Debugging – Debugging is the process of fixing an error in a program or system. Debugging is the act of discovering why a system does not work properly.

All software contains bugs!

The steps to debugging are as follows:

1. Reproduce the error

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2. Determine the problem exactly

Be sure to understand the exact problem. People often have difficulty determining describing a problem exactly. Take your time to understand the problem.

3. Eliminate the obvious

Bugs can be caused by a wide range of events: user error, network errors, software configuration problems, and more. Eliminate possible explanations as you troubleshoot the problem.

4. Divide up the process

Almost any task can be subdivided into parts. Divide the process into parts and determine which parts of the process are working and which are not. For example, if we are having trouble printing, try to determine if the problem is related to the network, the workstation, the specific printer, all printers, the specific software, or all software.

5. Reassess

Throughout the process of debugging make predictions and verify if your

predictions are accurate. This technique will help to evaluate if you are pursuing a good path. Reassess your assumptions often and walk through the process until you resolve the problem.

Algorithm – a precise and systematic method for producing a specified result.

API – Application Programming Interface. An application programming interface (API) is a set of functions, procedures, methods or classes that an operating system, library or service provides to support requests made by computer programs.

GUI – Graphical User Interface. The Windows Operating System Desktop is an example of a GUI.

RGB – Red, Green, Blue refers to the color display system for almost all computer monitors.

RGB is rendered in a hexadecimal code in HTML. The code for colors in HTML is as follows:

#RRGGBB where the first two digits define the red channel, the middle two digits define the green channel, and the last two digits define the blue channel.

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Hexadecimal RGB Code Color

#FFFFFF White

#000000 Black

#FF0000 Red

#00FF00 Green

#0000FF Blue

#FFFF00 Yellow

#00FFFF Cyan

#FF00FF Magenta

Literal - Computers can only do exactly what they are told. They are literal in the sense that they can only follow instructions from a computer program. Human beings use computers in conjunction with free will and intuition to achieve creative ends. Literal means to or from the letter.

Bits and Bytes

There are 8 bits in a byte. A bit is short for a binary digit. Computers store information as a series of bits. Often, human beings use hexadecimal codes to render bits more easily.

Binary Decimal Hexadecimal

0000 0 0

0001 1 1

0010 2 2

0011 3 3

0100 4 4

0101 5 5

0110 6 6

0111 7 7

1000 8 8

1001 9 9

1010 10 A

1011 11 B

1100 12 C

1101 13 D

1110 14 E

1111 15 F

ASCII

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contains 256 symbols due to its 8 bit length. For example, 28 _{= 256. The ASCII}

character set, therefore, cannot render languages such as Bosnian.

Unicode

Unicode provides a unique number for each character in the writing systems of the world. Unicode provides a much more consistent and effective encoding strategy for

multilingual projects.

Analog Signal

An analog signal is a continuously varying representation of a phenomenon such as a sound wave.

Digital Signal

A digital signal is a discrete or step levels presentation of a phenomenon.

Sample

Sound digitization requires that an analog signal be sampled at regular intervals.

Sampling is simply taking measurements at regular intervals. The sampling rate is the number of samples taken per second. The Nyquist Rule is a guideline for determining the appropriate sampling rate of a signal. The rule states that the analog signal should be sampled at a rate that exceeds the highest signal frequency by at least two times. For example, human beings can hear up to roughly 20,000 Hz. Therefore, in order to build a quality digital signal, we should sample sound at no less than twice that rate, 40,000 Hz.

Compression

Compression is the ability to encode information with fewer bits than a given

representation. Compression techniques exploit redundant or unimportant information to reduce the size of a digital signal. Compression techniques exist for images, video, and sound. Compression represents a major advantage of digital information over analog information. MP3 is an example of a compression technique for digital audio. JPEG

compression is used for images. MPEG compression is used for digital movies.

Social Aspects of Internet Computing

The Professional Use of Email

1. Understand the limits of email

a. Not effective at conveying emotion

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e. Flames are email battles. If you find yourself angry at the keyboard, walk away and think before you reply.

2. Professional uses for email include: a. Ask about one topic at a time

b. Include the context of your response

c. Use an automated reply when you are unable to answer email d. Answer a backlog of emails in reverse order

e. Ask for permission before forwarding an email f. Use small and targeted email distribution lists

Protecting yourself with passwords

1. Select strong passwords

a. The longer the better. Make passwords at least 6 characters in length b. Use a combination of uppercase and lowercase letters

c. Use numbers and symbols in addition to mixed case letters 2. Change passwords frequently

Security Topics

Virus

A virus is a program that infects another program by embedding a copy of itself so that when the infected program runs, the virus makes copies of itself thereby infecting other programs.

Worm

A worm is an independent program that makes copies of itself from machine to machine across a network. Where a virus hides in another program, a worm moves across a network by itself.

Trojan

A trojan is a program that hides inside another program performing operations hidden from the user. Trojans are often used to collect passwords or other sensitive data with keystroke loggers.

Exploit

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Malware

Malware is a short term for malicious software. Viruses, worms, Trojans, and exploits are all malware.

How to catch malware

1. Email attachments 2. Copying software 3. Peer-to-peer exchange 4. New software

Phishing

Phishing is a technique to acquire sensitive information from users by cleverly posing as an official entity collecting information. Phishing scams are sent as spam to many users. Read messages very carefully and never send anyone sensitive information via email.

Intellectual Property

Software licenses give you the right to use the software, but the ownership remains with the company that markets it. Because you do not own the software, you do not have the right to sell it or give it away.

Shareware is software that is distributed freely over the Internet. If you like the software, then you pay the person who created it. Generally, shareware works on the honor system.

Freeware is software that is completely free in the sense that you can download it, use it, and share it. The creators of the software have given the application to the world with few if any strings attached.

Open Source software is free software where not only the program but also the source code for that program is available for public use.