Basic TCP IP TCP and UDP Communication

COMPUTER HARDWARE

A computer has electronic and mechanical parts known as hardware. That is, the physical components that make up a computer system is known as computer hardware. Hardware includes input devices, output devices, system unit, storage devices and communication devices. Without these components we would not be able to use the computer.

Input Devices:
An input device is any hardware component that allows you the user to enter data into the computer. There are many input devices. Some most widely used input devices are:

• A keyboard: You use the keyboard to type letters, numbers and symbols into the computer.
  
• A Mouse: The mouse is a pointing device that has a pointer that changes into different shapes as you use the mouse. You click the mouse by pressing and releasing the button. This action allows you to enter data when using a mouse.
  
• A Scanner: This input device copies from paper into your computer.
  
• A Microphone: The microphone is usually used for voice input into the computer.
  
• A Digital Camera: The digital camera allows you to take pictures that you can input into your computer.
  
• A PC Video Camera/Web Camera: The PC video camera allows you take both video and still images that you can input onto your computer.
  

Output Devices:
An output device is any hardware component that gives information to the user. Three commonly used output devices are:

1. A Monitor: This output device displays your information on a screen.
2. A Printer: This output device prints information on paper. This type of printed output is called a hard copy.
3. A Speaker: Sound is the type of output you will get from a speaker. 

The System Unit:

See the picture, it is the case that contains all the electronic components of any computer system, it is called the System Unit or Central Processing Unit of a computer. The electronic components are considered internal hardware seeing that they are inside the system unit and you cannot see when you look at the computer. These components inside the system unit are what process the data and really make the computer work. Internal components are as follows:

• Power Supply: The power supply converts electricity into the current works for the computer. When the computer is turned on the power supply allows converted electricity to travel to other components inside the computer.
• Motherboard: The motherboard is the circuit board that holds the main internal components of the computer together. On the motherboard there are three major cards; sound card that operates the sound, the video card that handles the graphics that you see on the monitor and the modem card which allows computers to communicate with each other. Also on the motherboard is the Central Processing Unit (CPU), processor or brain of the computer. The CPU controls information and tells the other components inside the computer what to do.
• RAM & ROM: RAM stands for Random Access Memory. This memory holds the information you are working with while the computer is turned on. Once you turn the computer off all the information that was in RAM will be gone. ROM stands for Read Only Memory. This memory holds information that you can only read, but not erase. Information in ROM is built in and is always there even when the computer is turned off.
• Disk Drives: The disk drive is the device that reads information that is on disk. Generally speaking most computers have three disk drives; Hard Disk Drive, Floppy Disk Drive and CD-ROM Drive. However, the Floppy Disk Drives are not used nowadays but have DVD-ROM Drives. While the hard disk is hidden inside the computer the Floppy, DVD-ROM and CD-ROM drives are accessible from the front of the system unit.

The hardware parts are labeled in the diagram.

1. Monitor

2. Motherboard

3. CPU

4. RAM

5. Expansion Cards / Graphics Card / Sound Card / Network Card

6. Power Supply

7. Optical Disc Drive

8. Hard Disk Drive

9. Keyboard

10. Mouse

COMPUTER SOFTWARE

The computer will not work without software. Software also call programs are the instructions that tell the computer what to do and how o do it. The two main categories of software are system software and application software.

The system software also called the operating system (OS) actually runs the computer. This software controls all the operations of the computer and its devices. All computers use system software and without the system software the application software will not work. The most common OS on a PC is the Windows operating system and for the Mac computer it would be the Mac operating system.

Application software is a program that allows users to a specific task on the computer. There are a number of different types of application software available to do many of the tasks we do daily. Four examples of common application software and what they are used for are:

• Word Processing Application: One word processing program is Microsoft Word. This program allows you to type letters, assignments and do any other written activity on the computer.
• Spreadsheet Application: Microsoft Excel is an example of a spreadsheet program. One can use this program to create charts and do calculations.
• E-mail Application: Outlook Express is an e-mail program that allows you to receive and send e-mails.
• Internet Application: Internet Explorer is a program that allows you to get connected to the Internet and look at Web sites like the one you are reading now.

The third category of computer software is malicious software or malware, computer software developed to harm and disrupt computers. Malware is closely associated with computer-related crimes.

COMPUTER - Questions & Answers

Q1.What is a computer?

       A. A computer is an electronic machine operating under the control of instructions.

Q2.How many generations of computers are there? 

       A. There are three generations of computers.

Q3.What are the categories of computers? 

       A. The categories of computer are supercomputer, mainframe computer and personal computer.

Q4.What is software? 

       A. Software is the program or instructions that make the computer work.

Q5.What is hardware? 

       A. Hardware is the physical and electronic component of the computer system.

Q6.What are storage media? 

       A. Storage media are the physical materials that user stores data, information and instructions on for future use.

Q7.What does the acronym CPU stands for? 

       A. CPU - Central Processing Unit.

Q8.What do the acronyms ROM and RAM stand for? 

       A. ROM – Read Only Memory & RAM – Random Access Memory.

Q9.What is the difference between input and output? 

       A. Input is what is entered into the computer, while output what you seen on the monitor or what is printed out.

Q10. What is the difference between data and information? 

       A. Data is what is entered into to the computer to be processed, while information is processed data.