Introduction to Computers Lecture By K. Ezirim

What is a Computer? An electronic device –Desktops, Notebooks, Mobile Devices, Calculators etc. Require instructions to operate Comprises of –Hardware –Software

Basic operations of Computers Input – accept data for processing Process – process data according to specified instructions/rules Output – produce results Storage – store results for future use

Computers are powerful? Performs information processing with –High speed –Reliability –Accuracy Store huge amount of data and information Communicates with other computers

Computer Data and Information Data –Collection of unprocessed information –Examples: text, numbers, images, audio, video Information –Outcome of processed data –Conveys meaning and is useful –Can be stored in memory

Computer Users People that use computers –Computer users, end users, or simply users Green computing –Users and manufacture contributing to reduce environmental impact of computing –Reduced electricity and waste generated

Hardware Components Input devices Processor Memory Output devices Storage devices Communication devices

System Unit and Peripherals System Unit –Processor, Memory and Storage devices Peripherals –Input and output devices –Also storage and communication devices

Input Devices Keyboards Mouse Touchpads Stylus Touchscreen Microphone Camera

System Unit Motherboard –main circuit board of the system unit. –Other electronic components are attached to it –Such as sound card, video card Processor, also called the Central Processing Unit Memory – RAM, measured in bytes

Storage Devices Hard disks Portable Hard disks Flash memory storage –Memory cards Optical disks – CDs, DVDs, Blu-ray disks Cloud storage – internet service that provide storage (free/paid)

Output Devices Printers Headphones Speakers Data Projectors Monitors etc.

Communication Devices Enables computers to exchange information (send and receive) Transmission media –Cables, telephone lines, cellular radio networks, and satellites –Wireless - no physical lines or wires eg. Satellites, cellular radio networks.

Computer Software Also called program Usually comes with a user interface Graphic User Interface (GUI) Installing and Uninstalling Divided into System and Application Software

System Software Programs that control the operations of a computer Operating Systems – coordinates all the activities among computer hardware devices –Microsoft Windows (Microsoft) –Mac OS (Apple) Utility Program – allows users to perform maintenance

Application Software Includes all applications designed to –make users more productive –Assist with personal task Examples –Word Processing: create, edit, format, print –Presentation: create visual aids

Application Software Examples –Spreadsheet: organize data in rows, columns and perform calculation on data –Database: organize data to allow easy access, retrieval and usage of data – create, send, receive, forward, store, print, and delete messages.

Network and the Internet Network –A collection of computers and devices connected together –Often wirelessly via communication devices and transmission media –Allows users to share resources – hardware, software, data, information –Saves time and money

Types of Networks Local Area Network (LAN) –Connects computers and devices in a limited geographical area Wireless LAN (WLAN) –Similar to LAN but uses no physical wires. Connects to a LAN. Wide Area Network (WAN) –Covers a large geographical area

The Internet Worldwide collection of networks Links businesses, governments, agencies, educational and financial institutions, and individuals Internet Service Provide (ISP) –Access provider: individual/business that provides access to Internet for free or fee.

World Wide Web (WWW) A popular Internet service Contains billions of documents called Web pages A web page –Contains text, graphics, animation, audio, and video and links to other web pages

World Wide Web (WWW) Website –A collection of web pages –Can be accessed using a Web browser Web Address or Uniform Resource Locator (URL) –A unique address assigned to web page

Searching the Web Primary use of the web –Search for specific information Search engines –program that finds websites, web pages, images etc related to a specific topic Subject Directory –Classifies web pages in organized set of categories or groups such as sports, entertainments etc.

Computer Viruses and Malware Computer Virus –Damaging computer program –Alters the way computer works without permission Worm –Computer program that copies itself repeatedly, using up resources

Computer Viruses and Malwares Trojan horse (after Greek myth) –Hides within or looks like a legit program –Certain actions trigger the Trojan horse Rootkit –Program that hides in a computer and allows someone to remotely control the computer

Computer Viruses and Malware Malware –Virus, Worm, Trojan horse, rootkit Antivirus programs –Protects the computer from malware –Identifies and removes malware

Thanks