Lesson 1: Introduction to Computers PDF

CHAPTER 1: Introducing Computer Systems 1 Introduction to Computers Preview and Objectives  Identify the various parts of a computer system and what each does.  Identify various Operating Systems.  Identify major software applications packages and what they do...

CHAPTER 1: Introducing Computer Systems 1 Introduction to Computers Preview and Objectives  Identify the various parts of a computer system and what each does.  Identify various Operating Systems.  Identify major software applications packages and what they do.  Know how to use common features of windows and the desktop.  Know how to organize files and folders using Windows Explorer.  Be familiar with features common to Windows software.  Have a working knowledge of Microsoft Office software.  Use computers in the business workplace and other fields.  Explain why Information Systems are so important today and how they are transforming organizations and management  Identify appropriate goals and objectives for organizations.  Use various positioning frameworks to analyze an organization’s dependence on Information systems.  Produce /devise an Information Systems plan/strategy for an organization. 2 Introduction to Computers  Definition of a computer  By definition, a computer is an electronic device that inputs data, processes data(converting it into information that is useful to people) outputs and stores information.  Computers are controlled by programmed instructions that transform the data into meaningful information.  Generally a Computer is a device that accepts input, processes it, stores data, and produces output. 3 Introduction to Computers Information Processing Cycle  Steps followed to process data  Input  Processing  Output  Storage 4 Introduction to Computers  Input  Input: Information provided to the computer by a person, the environment, or another computer. Examples of Input  words and symbols  numbers  pictures  audio signals from a microphone  signals from another computer  temperature, speed, pressures, etc. from sensors 5 Introduction to Computers Processing  Processing - manipulation of data.  Data are symbols that represent raw facts, objects, and ideas about people, places, events, and things that are of importance in an organization.  A computer program or software is a series of instructions that tell a computer how to carry out a processing task.  Examples of Processing  Arithmetic calculations  Sorting a list  Modifying pictures  Drawing graphs 6 Introduction to Computers  Output  Output - the result produced by a computer after processing the data.  Output device –displays, prints, or transmits the results after processing.  Examples of Output  images on a monitor  printed documents  sounds  signals to device controllers 7 Introduction to Computers Memory and Storage  Memory - the area of a computer that temporarily holds data that is being processed or waiting to be processed, stored, or output.  Storage - The area where data can be left on a permanent basis while it is not needed for processing.  Examples of Storage  magnetic disks  CD-ROM (Compact Disk Read-Only Memory)  magnetic tapes  Flash disk  Memory card  Floppy disk 8 Introduction to Computers Personal and Home Uses of Computers  Computers allow people with disabilities to do normal activities.  Shopping online  Playing games with other people  Work from home  Entertainment such as listening to music, watching videos etc.  Enable communication through the use of (electronic mails) e-mails , chats etc. Introduction to Computers 9 Business Uses of Computers  Computers allow companies to keep large amounts of information at hand.  Databases  Makes ordering and tracking resources quicker and easier.  Allows people to have meetings from different locations.  Helps in information management which eases the process of decision making.  Computers allow people across the world to communicate easily. Introduction to Computers 10 Educational Uses of Computers  The Internet allows access to hundreds of online research materials.  Allows colleagues to correspond quickly about ongoing research.  Eases the process of analysing research data. Introduction to Computers 11 Parts of a Computer System  Computer systems have four parts  Hardware  Software  Data  User (people) 12 Introduction to Computers  Parts of a Computer System  Computer hardware:  A computer's hardware consists of electronic devices; the parts you can see and touch.  Inotherwords these are tangible parts of a computer.  The term "device" refers to any piece of hardware used by the computer, such as a keyboard, monitor, modem, mouse, etc.  These are mechanical devices that make up the computer. 13 Introduction to Computers Computer Hardware Components  Display Device (Monitor or LCD screen)  System Unit  Floppy disk drive  CD ROM drive  Hard disk drive  Keyboard  Mouse 14 Introduction to Computers  Other hardware components  DVD drive (Digital Versatile Disk)  CD writer (Compact disk)  Sound card and speakers  Modem (Modulate and Demodulate)  Printers. 15 Introduction to Computers Peripherals  A peripheral device designates equipment that might be added to a computer system to enhance its functionality.  Examples:  Printer  Digital camera  Scanner  Joystick 16 Introduction to Computers  Parts of a Computer System  Computer Software  Is the set of instructions that makes the computer perform tasks.  The software is a part of the computer you cannot touch but is very important.  The software is all the programming that makes the computer run; controlling everything that the computer does.  For any computer to function, it needs to have software installed on it. 17 Introduction to Computers  Parts of a Computer System  Data:  Data consists of raw facts, which the computer can manipulate and process into information that is useful to people.  Computerized data is digital, meaning that it has been reduced to digits, or numbers. The computer stores and reads all data as numbers.  Users:  People operating the computer.  Tell the computer what to do. 18 Introduction to Computers  Essential Computer Hardware  A computer’s hardware devices falls into one of the four categories; 1. Processor 2. Memory 3. Input and Output 4. Storage 19 Introduction to Computers  Essential Computer Hardware  Processing Devices  The procedure that transforms raw data into useful information is called processing.  The processor is like the brain of the computer.  Organizes and carries out instructions from either the user or software.  Manipulate the data.  Most computers have several processors.  Central Processing Unit (CPU) refers to a computer’s processor. 20 Introduction to Computers Essential Computer Hardware  Memory devices  Memory is made up of one or more sets of chips that Store data or program instructions either temporarily or permanently. Memory is divided into two types: a) Random Access Memory (RAM)  RAM holds data and program instructions temporarily while the CPU works with them.  RAM is volatile, meaning it holds data only when the power is on. When the power is off, RAM's contents are lost.  The “random” in RAM implies that any portion of RAM can be accessed at anytime. This helps make RAM very fast.  More RAM results in a faster system. 21 Introduction to Computers  Essential Computer Hardware b) Read Only Memory (ROM)  Permanent storage of programs.  ROM is called non-volatile memory because it never loses its contents.  Holds instructions that the computer needs to operate.  Memory is measured in terms of:  Kilobyte (KB) - 1,000 bytes  Megabyte (MB) - 1,000,000 bytes  Gigabyte (GB) - 1,000,000,000 bytes  Terabyte (TB) - 1,000,000,000,000 bytes. 22 Introduction to Computers  Position of RAM and ROM on the MotherBoard 23 Introduction to Computers  Essential Computer Hardware  Input and Output Devices  Input devices accept data and instructions from the user or from another computer system.  Output devices return processed data to the user or to another computer system.  Input devices include: keyboard, mouse, scanner, digital camera, microphone etc.  Output devices include: monitor, printer, stereo speakers, headphones etc.  Communications devices (such as modems and network interface cards) perform both input and output, allowing computers to share information. 24 Introduction to Computers Essential Computer Hardware  Storage Devices  The purpose of storage is to hold data permanently, even when the computer is turned off.  Storage devices hold data not currently being used by the CPU.  Data is commonly stored on a magnetic or optical disk.  A disk drive is a device that reads data from and writes data to a disk. Most new computers feature a floppy disk drive, a hard disk drive, and an optical disk drive.  The most common optical storage devices are CDROM and DVD-ROM drives. 25 Introduction to Computers Computer Software  Software is a set of instructions that drive a computer to perform specific tasks.  These instructions tell the machine’s physical components what to do.  A set of instructions is often called a program.  When a computer is using a particular program, it is said to be running or executing the program.  The two most common types of programs are system software and application software. 26 Introduction to Computers Computer Software 1) System software: Is any program that controls the computer’s hardware or that can be used to maintain the computer in some way so that it runs more efficiently.  System Software provides a platform for running application software.  There are three basic types of system software: a) An operating system tells the computer how to use its own components. All computers require an operating system.  The OS tells the computer how to interact with the user and its own devices.  Examples of operating systems include Windows, Macintosh operating system and Linux. 27 Introduction to Computers Computer Software b) A network operating system allows computers to communicate and share data across a network while controlling network operations and overseeing the network’s security. Example is Windows server 2003. c) A utility is a program that makes the computer system easier to use or performs highly specialized functions.  Utilities are used to manage disks, troubleshoot hardware problems, and perform other tasks that the operating system itself may not be able to do. For example a Symantec antivirus, Partition Magic etc. 28 Introduction to Computers Computer Software 2) Application Software: Tells the computer how to accomplish specific tasks, such as word processing or drawing, for the user.  Some of the major categories of these applications include:  Word processing software for creating text-based documents  Spreadsheets for creating numeric-based documents such as budgets.  Presentation programs for creating and presenting electronic slide shows.  Graphics programs for designing illustrations or manipulating photographs, movies etc.  Database management software for building and manipulating large sets of data such as names, addresses etc. 29 Introduction to Computers Data and Information  Data are the words, numbers, symbols and graphics that describe people, events, things, and ideas.  Data becomes information when it is used as the basis for initiating some action or for making a decision.  Information are the words, numbers, and graphics used as the basis for human actions and decisions.  A set of data that has been given a name is called a file.  A file that a user can open and use is called document.  A folder is a place where groups of computer files and other folders can be kept and organized. 30 Introduction to Computers  Files  A file is a named collection of data, stored on a storage medium such as a hard disk.  There are two types of files  Data files contains text, images, or other data that can be used by a program.  Executable files contains programs or instructions that tell the computer how to perform a task.  Filename extensions describe a file’s contents. For example Executable files usually end in.exe, word files end in.doc, adobe acrobat documents end in.pdf etc. 31 Introduction to Computers Extensions and Formats  A filename might be followed by a filename extension that further describes the file contents.  Word files end in.doc  Excel files end in.xls  The file format is the arrangement of data in a file and the coding scheme that is used to represent the data.  The native file format is the format that is saved by the application that created it. 32 Introduction to Computers  Assignment 1 1. Discuss the history and evolution of computers. (maximum. 3 pages). 2. Computers are used more extensively than ever for tasks such as banking, investing, shopping and communicating. Do you see this trend as having a positive or a negative impact on our society and economy? Give reasons to support your answer. (minimum of 500 words). 33 Introduction to Computers