Introduction to Computers

• This module is designed to help in mastering computer operations
• The module is divided into three lessons: Introduction to Computer, Computer Hardware, and Computer Application Software

Learning Objectives

• Define computer
• Develop appreciation for computer uses
• Explain the functions of computer hardware
• Identify computer hardware
• Appreciate the importance of computer hardware in a computer system
• Explain the function of application software
• Enter and save data using appropriate application software
• Appreciate choosing the right application software for a specific purpose

Introduction to Computers

• A computer is an electronic device to manipulate data
• Computers can store, retrieve, and process data
• Computers can be used to type documents, send emails, play games, browse the web, and edit or create spreadsheets, presentations, and videos

Hardware vs. Software

• Hardware: Physical parts of a computer (keyboard, mouse, internal parts)
• Software: Sets of instructions for hardware (web browsers, games, word processors)

Types of Computers

• Desktop computers: Designed to be placed on a desk, including the case, monitor, keyboard, and mouse
• Laptop computers: Portable, battery-powered
• Tablet computers: Handheld, use a touch-sensitive screen rather than a keyboard and mouse
• Server: Provides information to computers on a network and stores/shares files internally for many businesses
• Smartphones: Cell phones that perform many computer functions, including internet browsing and playing games
• Wearables: General term for devices worn throughout the day (fitness trackers, smartwatches)
• Game consoles: Used for playing video games on a TV
• TVs: Include apps for accessing online content, like streaming video

PCs and Macs

• Personal Computers(PCs) include IBM PC compatibles and typically include Microsoft Windows
• Macintosh (Macs): Introduced in 1984, the first widely sold personal computer with a graphical user interface (GUI), made by Apple, uses Mac OS X operating system

Computer Hardware

• Physical, touchable, electronic and mechanical parts of a computer

System Unit

• The main part of a microcomputer, sometimes called the chassis
• It contains the Motherboard, Microprocessor, Memory Chips, Buses, Ports, Expansion Slots and Cards

Motherboard/Mainboard/System Board

• The main circuit board containing circuits and components of running the computer

CPU (Central Processing Unit)

• The main "brain" or "heart"
• It performs instructions/calculations and manages the flow of information

Primary Storage (Internal Storage/Main Memory)

• The computer's working space holding data, instructions, and processed data that is waiting to be sent to secondary storage
• Physically comprised of RAM chips

Memory Types

• ROM (Read Only Memory): Non-volatile (holds data even when power is off)
• RAM (Random Access Memory): Volatile (holds data only when power is on; contents lost when power is off)

Expansion Bus

• A data pathway between hardware components inside/outside a computer
• Connects the CPU parts to each other and to other important parts

Adapters

• Enable the computer to use a peripheral device for which it lacks necessary connections or circuit boards by connecting to printed-circuit boards
• Used to permit upgrading to a new hardware

Power Supply Unit (PSU)

• Positioned in the PC case, next to the motherboard which converts standard (120vac) into DC voltages used by the other components

Hard Disk Drive (HDD)/Hard Drive

• Magnetic storage device that is installed inside the computer for permanent data storage

Optical Drive

• A storage device that uses lasers to read data on optical media, including Compact Discs (CD), Digital Versatile Discs (DVD), and Blu-ray Discs (BD)

Digital Versatile Disc (DVD)

• Designed to optically retrieve data stored on it by moving a backs and forward a laser near the surface of the disc

Input and Output Devices

• Devices connected to a personal computer

Input Device

• Accepts data/instructions from the user/another computer system

Output Device

• Displays results after the computer has processed input data

Input Devices - Keyboard Entry

• Data is imputed through a keyboard
• Keyboard is an imput device developed for PC using a circular 6-pin Mini-Din connector that pligs into the back of the computer

Input Devices - Direct entry

• Direct-entry devices create machine-readable data on magnetic media or feed it directly into the CPU, without needing data to be keyed

Direct Entry Devices - Pointing Devices

• Input device used to move a pointer (cursor) on screen
• Mouse: most common pointing device which usually have two buttons and scroll wheels

Type of Input Devices

• Touch screen: sensitive to touch using finger or stylus and is used in ATMs, retail terminals, car navigation, and industrial controls
• Light pen: light-sensitive stylus wired to a video terminal and used to draw pictures or select menu options
• Digitizer tablet: used for sketching or tracing images, uses wired/wireless pen or puck
• Scanning devices read text or illustrations printed on paper and translate the information into a usable form
• Voice Input Devices: such as speech or voice recognition systems that allow users to speak directly to the computer

Output devices

• Computer Display Monitor: displays information in visual form using text and graphics
• The portion of the monitor that displays the information is called screen or video display terminal

Types of Monitors

• CRT (Cathode Ray Tubes): Older displays for desktop PCs, relatively big and heavy
• LCD (Liquid Crystal Display): Common in laptops, now available for desktops
• LED (Light Emitting Diode): Uses light emitting diode in almost every electrical and electronic products

Additional type of Output Devices

• LCD Projectors: Utilize two sheets of polarizing material with liquid crystal solution that electric material that allows light to pass through
• Smart Board: Has a touch sensitive transparent panel
• Printer: A device to print text or illustrations on pater

Types of Printers

• Ink-Jet/Bubble-Jet: Sprays ink onto paper, producing high-quality text and graphics
• Laser: High-quality text and graphics using same technology as copy machines
• LCD/LED: Similar to laser printers, but uses liquid crystals/light-emitting diodes to produce an image
• Line: Contains a chain or pins that print an entire line, fast but low quality
• Thermal: Inexpensive, pushing heated pins for use against heat-sensitive paper and used in calculators and fax machines

Audio Devices

• Speakers: Used to play sounds in computers either built into the unit or connected using cables

Computer Application Software

• Types of Computer Application Software: word processor; spreadsheet; presentation software; database management system; desktop publisher; graphics editor and web browser.

Word Processors

• Software used to create, store, and print documents e.g Microsoft Word, WordPro, AppleWorks.

Spreadsheet Software

• Used in a data file made up of rows and columns which sort data, arrange data, and manipulate data e.g. excel

Presentation software

• It helps a slideshow that address a topic
• Microsoft PowerPoint, Adobe Persuasion, Hypercard, OpenOffice Impress and Scala Multimedia.

Database Management System (DBMS) Software

• Controls the organization, storage, management, and retrieval of data in a database
• Microsoft Access, Oracle Database, MySQL and FoxPro.

Desktop Publishing Software

• Produces high-quality printed documents which is used to set difference typefaces and is used in illustrations in the text e.g Adobe InDesign, QuarkXPress and MS Publisher.

Web Browsers

• Used to locate and display Web pages
• Internet Explorer (IE), Mozilla Firefox, Opera and Google Chrome.

Graphic Software

• Or image editing software is a program or collection of programs that enable a person to manipulate visual images on a computer. Computer graphics can be classified into two distinct categories: raster graphics and vector graphics
• The most common example is Adobe Photoshop.

Saving Files - File names

• Identifier is a name used to uniquely identify a computer file stored in a file system

Saving Files - File Extension

• Ending of a file that helps identify file type e.g .MP3 or .docx

Saving Files - File Location/Path

• Defines the file/folder location in a computer's file system

Storage Devices

• Hardware capable of temporary and permanently holding information with two storage devices i.e primary storage which is the Random Access Memory and the secondary device which is a hard drive.

Primary Storage Device

• Where the memory of time is for a short time and while the computer works
• RAM (random access memory) and cache

Secondary Device

• Holds data until it is deleted or overwritten and about two orders of magnitude cheaper

Types of Storage Drives

• HDDs (Hard Disk Drives): Are non-volatile with on or more disk platters housed inside the air-sealed case
• SSDs (Solid-State Drives): Storage mediums which use non-volatile memory and have no moving parts
• USB Thumb Drives: Portable portable storage devices
• SD Cards: Used in electronics
• CDs: Invented by James Russell
• DVDs: Significant amount than standard compact disc and is commonly used to store a dvd
• Floppy Diskette: Stored electronic data in a computer but was very expensive at the time

Modern Storage Devices

• Today's computers use mainly SSD and flash drives