Hardware and software basics

APPENDIX AHARDWARE AND SOFTWARE BASICSCopyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.Overview HARDWARE AND SOFTWARE BASICSHardware BasicsComputer CategoriesSoftware BasicsINTRODUCTIONInformation technology (IT) - Any computer-based tool that people use to work with information and support the information and information-processing needs of an organizationHardware - Consists of the physical devices associated with a computer systemSoftware - The set of instructions that the hardware executes to carry out specific tasksHARDWARE BASICSComputer - An electronic device operating under the control of instructions stored in its own memory that can accept, manipulate, and store dataHardware components include:Central processing unit (CPU)Primary storageSecondary storageInput deviceOutput deviceCommunication deviceHARDWARE BASICSHARDWARE BASICSHARDWARE BASICSHARDWARE BASICSCentral Processing UnitCentral processing unit (CPU) (or microprocessor) - The actual hardware that interprets and executes the program (software) instructions and coordinates how all the other hardware devices work togetherControl unit - Interprets software instructions and literally tells the other hardware devices what to do, based on the software instructionsArithmetic-logic unit (ALU) - Performs all arithmetic operations (for example, addition and subtraction) and all logic operations (such as sorting and comparing numbers)Central Processing UnitThe number of CPU cycles per second determines the speed of a CPU Megahertz (MHz) - The number of millions of CPU cycles per secondGigahertz (GHz) - The number of billions of CPU cycles per second Central Processing UnitCPU speed factorsClock speedWord lengthBus widthChip line widthBinary digit (bit) - The smallest unit of information that a computer can processByte - A group of eight bits representing one natural language characterAdvances in CPU DesignComplex instruction set computer (CISC) chip - Type of CPU that can recognize as many as 100 or more instructions, enough to carry out most computations directlyReduced instruction set computer (RISC) chip - Limit the number of instructions the CPU can execute to increase processing speedVirtualization - A protected memory space created by the CPU allowing the computer to create virtual machinesPrimary StoragePrimary storage - The computer’s main memory, which consists of the random access memory (RAM), cache memory, and the read-only memory (ROM) that is directly accessible to the CPURandom Access Memory (RAM)Random access memory (RAM) - The computer’s primary working memory, in which program instructions and data are stored so that they can be accessed directly by the CPU via the processor’s high-speed external data busVolatility Cache memory Random Access Memory (RAM)Read-Only Memory (ROM)Read-only memory (ROM) - The portion of a computer’s primary storage that does not lose its contents when one switches off the powerFlash memory Memory cardMemory stickSecondary StorageSecondary storage - Consists of equipment designed to store large volumes of data for long-term storageMegabyte (MB or M or Meg) - Roughly 1 million bytesGigabyte (GB) - Roughly 1 billion bytesTerabyte (TB) - Roughly 1 trillion bytes Secondary StorageMagnetic MediumMagnetic medium - A secondary storage medium that uses magnetic techniques to store and retrieve data on disks or tapes coated with magnetically sensitive materialsMagnetic tape - An older secondary storage medium that uses a strip of thin plastic coated with a magnetically sensitive recording mediumHard drive - A secondary storage medium that uses several rigid disks coated with a magnetically sensitive material and housed together with the recording heads in a hermetically sealed mechanism Optical MediumOptical medium types include:Compact disk-read-only memory (CD-ROM) Compact disk-read-write (CD-RW) driveDigital video disk (DVD) DVD-ROM driveDigital video disk-read/write (DVD-RW)Input DevicesInput device - Equipment used to capture information and commandsInput DevicesOutput DevicesMonitorsOutput DevicesPrintersCommunication DevicesCommunication device - Equipment used to send information and receive it from one location to anotherDial-up accessCableDigital subscriber lineWirelessSatelliteCOMPUTER CATEGORIESFor the past 20 years, federally funded supercomputing research has given birth to some of the computer industry’s most significant technology breakthroughs including:Clustering Parallel processingMosaic browserCOMPUTER CATEGORIESComputer categories include:Personal digital assistant (PDA) LaptopTabletDesktopWorkstation Minicomputer Mainframe computerSupercomputerSOFTWARE BASICSSystem software - Controls how the various technology tools work together along with the application softwareOperating system software Utility software Application software Utility SoftwareTypes of utility softwareCrash-proof Disk imageDisk optimization Encrypt dataFile and data recovery Text protectPreventative security Spyware UninstallerApplication SoftwareTypes of application softwareBowserCommunicationData managementDesktop publishingEmailGroupwarePresentation graphicsProgrammingSpreadsheetWord processing