Two Major Parts of a Computer System A computer system consists of two major parts:o Hardwareo SoftwareIntroduction to Computer Concepts Hardware refers to all visible components. They performthe actual data processing work. Software refers to programs which are instructions thatdescribe how to do the processing work.Computer Hardware and Software-2--1-Computer Hardware ComponentsCentral Processing Unit (CPU) A computer consists of the following main hardwarecomponents: The brain of the computer A complex integrated circuit consisting of millions of electronicparts and is primarily responsible for converting input (data) intomeaningful output (information)1. Central Processing Unit (CPU)2. Main Memory3. Secondary Memory / Storage4. Input Devices5. Output Devices-3--4-

Central Processing Unit (CPU)Main Memory Data travels in and out of the CPUthrough a bus – a communicationsystem that transfers data betweencomponents inside the computersystem Responsible for holding data and programs as they are beingprocessed by the CPU Random access memory (RAM)o OS fileso Running programso Fast but volatileMachine cycle CPU processes the data byrepeatedly following the machinecycle Read-only memory (ROM)ooooBIOSPower-on self test (POST)FirmwareHolds built-in system data, not for running programs, non-volatile-5--6-Common Types of RAMSecondary Storage DevicesTable 3-1: Types of RAMType of RAMDescriptionVolatile ornonvolatileDynamic RAM(DRAM)Memory needs to be constantly recharged orcontents will be erasedVolatile Non-volatile and relatively cheaper than main memory Designed to store data for extended periods of time The type and amount of data helps to determine the most appropriatestorage device to useStatic RAM (SRAM)Memory can be recharged less frequentlythan DRAM, but can be more expensive thanDRAMVolatileFigure 3-5: Storage devicesMagnetoresistiveRAM (MRAM)Memory uses magnetic charges to storecontents, and can retain its contents in theabsence of powerNonvolatileFlash memoryFast type of memory that typically is lessexpensive than some other types of RAM,and can retain its contents in the absence ofpowerNonvolatile-7--8-

Storage Solutions (1 of 2)Storage Solutions (2 of 2)Hard DrivesCloud Storage Internal hard drives Storing electronic files on the Internet instead of a local computeroGoogle DriveoMicrosoft OneDriveoDropboxo Magnetic hard disk drives (HDDs)o Solid State Drive (SDD) External hard driveso Magnetic hard disk driveso Solid State Drive (SDD)o USB flash driveo Optical media-9-Input and Output Devices-10-Computer hardware Components Summary Input device: communicates instructions and commands to acomputero Examples: keyboard, mouse Output device: conveys information from the computer to theusero Examples: speakers, printers-11--12-

How Computers Represent DataHow Computers Represent Data Integer numbers are stored as binaryA computer is a Binary System All data are represented as binary numbers (a sequence of 1sand 0s). Bit: smallest piece of data. Has value 0 (off) or 1 (on). Byte: 8 consecutive bits. Other units for measuring data 1111 Text coding schemeo Kilobyte (KB) 1024 byteso Megabyte (MB) 1024 KBo ASCII (8 bits)A - 01000001o Unicode (16 bits)A - 0000000001000001 Other datao Gigabyte (GB) 1024 MBo Terabyte (TB) 1024 GB-13-o Imageso Videoo Audio-14-Pros and Cons of Different Types of Computers (1 of 3)Pros and Cons of Different Types of Computers (1 of 3)Desktop ComputerLaptop Computer Very portable due to its compact size Less powerful than desktop Memory and hard drive are about the only components that canbe upgradedTypically consists of a system unit, monitor, keyboard, and mouseMore powerful, more storageHardware components can be easily upgradedCan’t be moved easily-15--16-

Pros and Cons of Different Types of Computers (2 of 3)Pros and Cons of Different Types of Computers (3 of 3)All-in-One ComputerMobile Device Smartphone, Tablet, etc. Portable or handheld computingdevice Less powerful Not upgradeableMonitor and system unit are housed togetherTake up less space and easier to transportTypically more difficult to service or upgradeMore expensive than desktops-17--18-Standard Operating System FunctionsCategories of Software System Software: The software that runs a computer, includingthe operating system and the utilities Operating System (OS): a program that manages the completeoperation of your computer or mobile device and lets you interactwith it. Starting and shutting down a computer or device Managing programs Managing memory Coordinating tasks Configuring deviceso Windows, MacOS, Unix, Android OSo Most operating systems come installed on your computer or device Establishing an Internet connection Monitoring performance Application Software: programs that provide services to theuser. They solve specific problems, such as word processing,browsing the web, games, etc. Providing file management Updating operating system software Monitoring securityo Microsoft Officeo Google Chrome Controlling network access-19--20-

Operating System FeaturesDesktop Operating Systems Graphical user interface (GUI)OS Utilities: software developed to help maintain the computerWindows Desktop computers,laptops, and some tablets Software as a Service (SaaS): software accessed online via asubscriptionSupports the Cortana virtual assistant, touchscreen input,HoloLens headsets, and built-in apps such as theMicrosoft Edge browsermacOSMacintosh desktopcomputers and laptopsIncludes the Siri virtual assistant, coordination with Applemobile devices, and cloud file storageUNIXMainframes, web servers,workstationsMultitasking operating system with many versions, as thecode is licensed to different developersLINUXDesktop computers,laptops, and some tabletsDistributed under the terms of a General Public License(GPL), which allows you to copy the OS for your ownuse, to give to others, or to sellChromeOSChromebook laptopsBased on Linux, uses the Google Chrome browser as itsuser interface, and primarily runs web apps (an appstored on an Internet server that can be run entirely in aweb browser)o Google Appso DocuSign Open/closed source: software whose original source code ismade freely (or not freely) available and may (or may not) beredistributed and modifiedo Android OS (open source)o Microsoft Office (closed source)Notable features-21-Server Operating Systems-22-Mobile Operating SystemsOSWindowsServerNotable featuresThe server version of Windows. It includes advancedsecurity tools and a set of programs called InternetInformation Services that manage web apps and services.macOSServerSupports all sizes of networks and servers. One uniquefeature is that it lets authorized users access servers theiriPhones or other Apple devices.A multipurpose operating system that can run on a desktopPC or a server. Many web servers, which are Internetcomputers that store webpages and deliver them to yourcomputer or device, use UNIX because it is a powerful,flexible operating system.UNIXAvailable for-23-OSAndroidNotable featuresDeveloped by Google based on LINUX, and designed to berun on many types of smartphones and tabletsiOSRuns only on Apple devices, including the iPhone, iPad,and iPod; derived from macOS-24-

Pros and Cons of Different Types of Computers (2 of 3) All-in-One Computer Monitor and system unit are housed together Take up less space and easier to transport Typically more difficult to service or upgrade More expensive than desktops-17-Pros and Cons of Different T