STM101 - CHAPTER ONE COMPUTER OVERVIEW OVERVIEW OF INFORMATION TECHNOLOGY (IT) Information Technology refers to anything related to computing technology, such as networking, hardware, software, the Internet, or the people that work with these technologies. Many companies now have IT (Information Technology) departments for managing the computers, networks, and other technical areas of their businesses.

IT jobs include - Computer programming development, - Maintenance, network administration, - Computer engineering, Web development, - Technical support, and many other related occupations. Since we live in the "information age," information technology has become a part of our everyday lives.

Why do we use computers? Computers can be used to - Type documents, -send , -play games, -browse the Web. -edit or create spreadsheets, presentations, and even videos.

III- Computer Types: a-Personal Computer (PC) This type of computer began with the original IBM PC introduced in Other companies began creating similar computers, which were called IBM PC Compatible. All Personal Computers (often shortened to PC) are made by different companies such as IBM, HP, Lenovo, Dell and many more. They use the Microsoft Windows (XP, Vista, Win7, Win8) operating system.

b-Macintosh (Mac) The Macintosh computer was introduced in 1984, and it was the first widely sold personal computer with a graphical user interface. All Macs are made by Apple Company, Apple Inc., and they use the (Mac OS X) operating system.

c- Laptops Laptop computers are personal computers but are smaller than desktops. They are designed to be used on the user’s lap. Laptops are more portable than desktop computers because they come with a battery and AC-power that allows use almost anywhere.

d- Supercomputers Super computers are computers designed with extremely large storage capacity and very high possessing speeds which are at least ten times faster than other computers. These computers are used for websites (Facebook, Google, Twitter…), global weather forecasting, defense applications and geographical information systems.

e- Smartphone Smartphones are handheld mobile phones and are designed to do multiple tasks that computers can do, such as browsing the Internet and playing games.

f- Tablet Computers (Tablet) Tablets are handheld computers that are even more portable than laptops and netbook. Instead of a keyboard or touchpad, tablets use a touch- sensitive screen for typing and navigation. The IPad is an example of a tablet.

IV- COMPUTER USAGE (WHY DO WE USE COMPUTERS) We use computers because computers are: a- Fast Computer CPU can perform more than 10 million operations per second. CPU speed is measured in MHz (number of operation that a computer can do in 1 second).

b- Able to store a lot Computer systems can store large amounts of data, in the hard-drive and retrieved efficiently when it is needed.

C- Reliable The reliability of results processed by a computer is very high. If a program is executed any number of times with the same set of data, every time the results will be the same.

Cheap The computer helps to hold down the costs of labor, energy and paperwork. As a result, computers help reduce the costs of goods and services in the companies and organizations.

V- Advantages of using computers: Computers have many advantages which can be summarized as in the following points: 1. Computers can help to automate various tasks that user cannot do manually. 2. Computers can help to organize data and information. 3. Computers can help to make work much easier. 4. Computers can help the user to communicate with friends and other people. 5. Computers can help to search and find information quickly. 6. Computers can help save time and money. 7. Computers can help save resources and space.

VI- COMPUTERS’ DOMAIN OF WORK (WHERE DO WE USE COMPUTERS?) A - Banking Computers are used to speed up the banking process which helps to offer same-day services efficiently and effectively. Computers help to track customers’ details, transactions and account details

b - Communication Computers help people communicate with each other over distance though - video calls, audio calls, - social network websites such as Facebook and Twitter. Computers are also used for business communication.

C- Transportation Computers are used to -run rapid transit systems - load containerships, - track trains across the country, -safeguard airport takeoffs and landings, -monitor air traffic, -schedule travel. -customer services such as ticket reservations and purchasing

D- Education - Computers allow students to access their coursework - marks, study materials from almost anywhere through online education systems such as Moodle and LAMS. - It also helps teachers and lecturers to organize students’ marks and send notifications and comments.

e- Office Work Computers are used in offices - to assist managers to track records -write letters, prepare budgets -draw graphs and charts -publish newsletters and advertisements.

F- Health and Medicine Computers are used in - hospitals to provide cross- sectional views of patients’ bodies - to assist doctors in correctly diagnosing diseases types. - assist doctors in recommending the correct medicine for patients

RELATION BETWEEN HARDWARE, SOFTWARE AND USERS All types of computers have three components in common: 1.users. 2.software 3.Hardware

1.Users are the people who use the computer and give the computer instructions to do work and to achieve specific tasks 2. Software is a collection of computer instructions that tell the hardware what to do and how to do it. There are two types of software: Application software (web browsers, games, and word processors) Operating systems (XP, Vista, Win7, Win8) 3.Hardware is any physical components of the computer. There are two types: Internal components such as RAM, Hard drive, Processor. External components such as Keyboard, Mouse, Monitor.

What makes one computer better than other computers? A- Hard Disk Drive HDD The Hard drive is the primary disk storage which affects the computer’s performance speed.

A hard drive has two factors that affect the computer speed 1.the speed of Reading/Writing 2.the size of the hard drive the size of hard drive plays a very small role in the performance of a computer. The capacity of a hard drive is measured in gigabytes (GB).gigabytes 1GB= 1024 MB 1MB = 1024KB 1KB=1024B.

B- Random Access Memory (RAM) RAM is temporary memory that accommodates software programs and data files as well as the operating system which helps to run the computer program. Therefore, whenever a program has been opened, it gets loaded from the hard drive into the RAM. This is because reading data from the RAM is much faster than reading data from the hard drive. Thus, the more RAM computer has the faster it will be. RAM capacity is measured in GB.

C- Central Processing Unit (CPU) The CPU is the primary driver of how fast a computer works. The operating frequency of the CPU (also known as the clock speed) The clock speed determines how fast it can process instruction.

The speed of the CPU is measured in terms of Hertz, and it is usually lies in the megahertz (MHz) or gigahertz (GHz) range. A megahertz means that the CPU can process one million instructions per second whereas a gigahertz CPU has the capability to process one billion instructions per second. The faster the clock, the more instructions the processor can complete per second.

d- Video Graphics Array (VGA) A Graphics card is used to display better pictures and overall performance to the computer. Graphics cards help games look and play better and give better resolution. A graphics card is a plug in card used to replace or update the normal video in the computer. A graphics card has its own RAM (memory) which it will use in place of taking the computer's RAM. This helps computers run faster and better. The capacity of a graphic is measured in GB, the same as RAM.