What is Computer Hacking?

Computer hacking is the practice of modifying computer hardware and software to accomplish a goal outside of the creator’s original purpose. People who engage in computer hacking activities are often called hackers. Since the word “hack” has long been used to describe someone who is incompetent at his/her profession, some hackers claim this term is offensive and fails to give appropriate recognition to their skills.
Computer hacking is most common among teenagers and young adults, although there are many older hackers as well. Many hackers are true technology buffs who enjoy learning more about how computers work and consider computer hacking an “art” form. They often enjoy programming and have expert-level skills in one particular program. For these individuals, computer hacking is a real life application of their problem-solving skills. It’s a chance to demonstrate their abilities, not an opportunity to harm others.

Authentication

Authentication is the process of determining whether someone or something is, in fact, who or what it is declared to be. In private and public computer networks (including the Internet), authentication is commonly done through the use of logon passwords. Knowledge of the password is assumed to guarantee that the user is authentic. Each user registers initially (or is registered by someone else), using an assigned or self-declared password.

or this reason, Internet business and many other transactions require a more stringent authentication process. The use of digital certificates issued and verified by a Certificate Authority (CA) as part of a public key infrastructure is considered likely to become the standard way to perform authentication on the Internet. 

CAD (computer-aided design)

CAD (computer-aided design) software is used by architects, engineers, drafters, artists, and others to create precision drawings or technical illustrations. CAD software can be used to create two-dimensional (2-D) drawings or three-dimensional (3-D) models.
CAD/CAM (computer-aided design/computer-aided manufacturing) is software used to design products such as electronic circuit boards in computers and other devices.

Computer Hardware Explained

MOTHERBOARD

The motherboard is a set of computer hardware components arranged so that they are physically connected and can easily communicate between each other. The motherboard makes it easy to attach all major hardware components of a computer. In what follows we will discuss these components.

CPU(Central Processing Unit)

The CPU is the most important piece of hardware in any computer. It manages all of the computer operations, calculations and tasks and manages, command and direct all the other components of a computer system.

Different CPU run at different speeds where the speed here is measured in terms of number of basic operations (cycles) per unit of time (usually the second). It is usually expressed in gigahertz. (1 gigahertz = 10⁹ cycles / second)

Usually a computer with a higher CPU speed runs faster, however it is important to understand that there are other computer hardware items that greatly affect the speed of a computer.

The CPU has two major parts: The Arithmetic Logic Unit (ALU) which carry all arithmetic and logic operations and the Control Unit which manages and control all instructions. 

RAM(Random Access Memory)

The RAM makes space available for your computer to read and write data to be accessed by the CPU. The computer reads data from a RAM faster than reading it from the hard drive and therefore adding more RAM to your computer makes it run a lot faster. RAM does not retain data when the computer is switched off hence the name of volatile memory.

ROM(Read Only Memory)

ROM contains data that cannot be modified and hence retain it even when the computer is switched off.

MODEM(Modulator-Demodulator)

A modem is an electronic device that enables a computer to communicate with other computers over a network. A modem, for example, allows you to connect to the internet using cables and telephone lines. Information in a computer is in digital form whereas information sent over telephone lines is analog. The modem converts digital information into analog and vice versa.

Sound Card

A sound card enables the computer to produce sounds to be broadcast through speakers and also to process sounds received through a microphone.

Graphics Card

Graphics cards enable the computer to transform data into pictures to be displayed on the monitor. Many graphics cards now have their own RAM and "coprocessor" which make them faster at processing data and displaying it.

Input Devices

Output devices are used to enter data into the computer and also instruct it on what to do. The keyboard, mouse, touchpad, joystick, microphone and scanner are all examples of input devices.

Output Devices

The monitor, printer, speakers are all exmaples of output devices. Their function is to transform all output information into text, animated and static images and sound.

 

WLAN - Wiretess network

Wireless (WIFI) networks are just like fixed LANs but instead of using cables, devices are linked by radio waves. Each computer in a wireless network requires a wireless network interface card (MC). These can be built in or  you can use plug-in adaptors. These allow each component in the network to communicate with a wireless access point (AP) to create a wireless local area network (WLAN).

Networks. LAN and WAN

LANs (Local Area Networks) are the networks that you see in most offices, schools and some homes. They usually need the following hardware in order to operate: 1) A Network File Server is a dedicated computer that runs the software needed by the network and stores the files that users have created. 2) Terminals are individual workstations that give access to the network. Using a terminal gives access to the network’s software and files. 3) If a group of terminals share use of a printer then the system needs a Print Server. If two or more documents are sent to the printer at the same time the print server will put them into a queue. Users can then carry on with other work whilst waiting for the document to be printed. 4) For the network to operate data needs to be sent to and from all parts of the network. This can be done using wire cables or fibre optic cables, or via radio signals.

Note — a LAN doesn’t have to include a server. LANs can be as simple as two or three computers linked together for the sharing of files or software.

WANs are long  range Networks

1) WAN is short for Wide Area Network. They are used when the computers that need to be connected together are in different places. 2) Like LANs, WANs need servers to operate the network, but users connect up to the network using modems, usually connected to the telephone system. Wireless technology such as microwaves or satellite can also be used. 3) WANs are used by companies who have employees working away from the firm’s main sites. A good example would be oil exploration engineers who work in remote parts of the world. They’re also used by firms who have a lot of teleworkers. 

Networks.

To Connect you need Special Hardware and Software

1.- Most people access the Internet using a PC connected to a normal telephone line. Computers are attached to a telephone line via another piece of kit called a ADSL modem or DSL modem or usually called router.
2.- To connect to the Internet, you use your modem-router ( router ) to connect to an Internet Service Provider (ISP) — these companies have computers permanently connected to the Internet. All the information sent from your PC goes via the ISP. 3.- The two most important pieces of software you need are a web browser to display web pages, and an e-mail client, which transmits and receives e-mail from a PC. 4.- Web browsers sometimes need plug-ins — small programs — before they can play certain types of multimedia files, like videos for example.

What is the email?

E-mail or electronic mail uses networked communication systems to transmit messages. Also documents containing information may be attached and sent along these messages. Because of the networked nature of the communication systems used to send electronic mails, these may be sent to users anywhere in the world in a matter of seconds. The speed and large amount of data that these communication systems can handle have changed the way people communicate with each other.
When you send an email to a given address, your ISP (Internet Service Provider which is the local company that provides your internet connections and maintenance) uses its computers and communication systems to locate that address and makes sure the email gets there.
Received e-mails are stored in mailboxes until you open them for reading. E-mails may be stored, deleted or forwarded to other people.

What is the Internet?

The internet is a system of interconnected networks of computers that communicate easily to one another and exchange large amount of documents written in Hyper Text Markup Language (HTML). The internet helps you find and share information. You can communicate with people via e-mail. You can chatt to others, shop online, listen to music, play games. You can also create your own online store and sell products. You can learn and study online. It is almost impossible to list all what you can use the internet for. Internet advertising has become one of the most effective ways of marketing products and can reach various places all over the world.
A very well known internet service is the World Wide Web (WWW). It is based on Hyper Text which is a set of rules in writing web pages with links to other pages. In WWW, the interaction of the client (computer seeking information) and the server (computer that has the information) is made possible by two important features of the web and these are the HTML language and the HTTP protocol which is a set of rules used to communicate between server and client. A server contains pages with information written in HTML language.

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Fig. 1 - Client Server Relationship Browsers such as the Internet Explorer, Firefox, Google Crome and Safari are software applications that may be used to navigate and view internet resources such as text and graphics. Once HTML pages reach your computer, browsers translate HTML documents into text and images and display them on your screen.
In order to use the internet, you need to connect to it and for this you need the following:

1. A computer
2. A broadband modem ( cable and ADSL) or a modem with a phone line. Note that broadband is much faster than phone line.
3. An Internet connection
4. An Internet account with an Internet Service Provider (ISP)- (a company that provides Internet access.)
5. A browser software such as Internet Explorer, Google Crome, Safari, ...

What is the difference between BIOS and CMOS?

Often the BIOS and CMOS can be confused because instructions may either indicate to enter the BIOS Setup or the CMOS Setup. Although the setup for BIOS and CMOS is the same, the BIOS and CMOS on the motherboard are not.

If you have already read the above BIOS and CMOS definition links you should now know that the BIOS and CMOS are two different components on the motherboard. The BIOS on the motherboard contains the instructions on how the computer boots and is only modified or updated with BIOS updates, the CMOS is powered by a CMOS battery and contains your system settings and is modified and changed by entering the CMOS Setup.

Although the setup is often referred to as the BIOS and CMOS setup, we suggest you only refer to the setup as "CMOS Setup" as it is more appropriate. Computer Hope often refers to the setup as BIOS and CMOS Setup to help users who are looking for one instead of the other.

How to enter the BIOS or CMOS setup.

New computers

Thankfully, computers that have been manufactured in the last few years will allow you to enter the CMOS by pressing one of the below five keys during the boot. Usually it's one of the first three.

• F1
• F2
• DEL
• ESC
• F10

A user will know when to press this key when they see a message similar to the below example as the computer is booting. Some older computers may also display a flashing block to indicate when to press the F1 or F2 keys.

Press <F2> to enter BIOS setup

If your computer is a new computer and you are unsure of what key to press when the computer is booting, try pressing and holding one or more keys the keyboard. This will cause a stuck key error, which may allow you to enter the BIOS setup.
Once you've successfully entered the CMOS setup you should see a screen similar to the below example.

BIOS

Short for Basic Input/Output System, the BIOS or System BIOS is a chip located on all computer motherboards that contains instructions and setup for how your system should boot and how it operates. In the picture to the right, is an example of what a BIOS chip may look like in your computer.The BIOS includes instructions on how to load basic computer hardware and includes a test referred to as a POST (Power On Self Test) that helps verify the computer meets requirements to boot up properly. If the computer does not pass the POST, you will receive a combination of beeps indicating what is malfunctioning within the computer.

Types of Operating Systems

Operating systems usually come preloaded on any computer that you buy. Most people use the operating system that comes with their computer, but it is possible to upgrade or even change operating systems.

The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, and Linux.

The Windows, OS X, and Linux logos

Modern operating systems use a Graphical User Interface, or GUI (pronounced "gooey"). A GUI lets you use your mouse to click on icons, buttons, and menus, and everything is clearly displayed on the screen using a combination of graphics and text.

What is an Operating System?

An operating system is the most important software that runs on a computer. It manages the computer's memory, processes, and all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's "language." Without an operating system, a computer is useless.

The Operating System's Job

You've probably heard the phrase boot your computer, but do you know what that means? Booting is the process that occurs when you press the power button to turn your computer on. During this process (which may take a minute or two), the computer does several things:

• It runs tests to make sure everything is working correctly.
• It checks for new hardware.
• It then starts up the operating system.

What Is the Meaning of Computer Education?

Computer labs like this one are common in schools.

Computer technology is an integral part of modern life and contemporary education. Computer education is necessary because students will continue to use computer technology in their academic and professional lives.