software application to business

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Software Applications inSoftware Applications in

BusinessBusinessNaveed Umar Naveed Umar



Computer Computer

AA c omputer c omputer isis aa machinemachine thatthat manipulatesmanipulates datadataaccordingaccording toto aa listlist of of instructionsinstructionsM odernM odern computerscomputers areare basedbased onon comparativelycomparativelytinytiny integratedintegrated circuitscircuits andand areare millionsmillions toto billionsbillionsof of timestimes moremore capablecapable whilewhile occupyingoccupying a a fractionfractionof of thethe spacespace. .

Today,Today, simplesimple computerscomputers maymay bebe mademade smallsmallenoughenough toto fitfit intointo aa wristwatchwristwatch andand bebe poweredpoweredfromfrom aa watchwatch batterybattery



P ersonal ComputersP ersonal Computers

P ersonalP ersonal computerscomputers inin variousvarious formsforms areare iconsiconsof of thethe InformationInformation AgeAge andand areare whatwhat mostmost peoplepeoplethinkthink of of asas "a"a computer"computer"; ; however,however, thethe mostmostcommoncommon formform of of computer computer inin useuse todaytoday isis thetheembeddedembedded computer computer. .EmbeddedEmbedded computerscomputers areare small,small, simplesimple devicesdevicesthatthat areare usedused toto controlcontrol other other devicesdevices for for exampleexample; ; theythey maymay bebe foundfound inin machinesmachinesrangingranging fromfrom fighter fighter aircraftaircraft toto industrialindustrial robots,robots,digitaldigital cameras,cameras, andand children'schildren's toystoys..



How c omputers workHow c omputers work

AA generalgeneral purposepurpose computer computer hashas four four mainmainsectionssections: :

TheThe ArithmeticArithmetic andand LogicLogic UnitUnit (ALU),(ALU),TheThe ControlControl UnitUnitTheThe M emoryM emory &&TheThe InputInput andand outputoutput devicesdevices (collectively(collectively termedtermedI/O)I/O)..

TheseThese partsparts areare interconnectedinterconnected by by busses,busses,oftenoften mademade of of groupsgroups of of wireswires..



Central processing unit &Central processing unit &M

icroprocessor M

icroprocessor TheThe controlcontrol unit,unit, ALU,ALU, registers,registers, andand basicbasicI/OI/O (and(and oftenoften other other hardwarehardware closelycloselylinkedlinked withwith these)these) areare collectivelycollectively knownknownasas aa centralcentral processingprocessing unitunit (C P U)(C P U)..EarlyEarly C P UsCP Us werewere composedcomposed of of manymanyseparateseparate componentscomponents butbut sincesince thethe midmid--

19701970ss CP

UsCP

Us havehave typicallytypically beenbeenconstructedconstructed onon aa singlesingle integratedintegrated circuitcircuitcalledcalled aa microprocessor microprocessor. .



HardwareHardware

TheThe termterm hardwarehardware coverscovers allall of of thosethose partsparts of of aacomputer computer thatthat areare physicalphysical objectsobjects. .

CircuitsCircuitsDisplaysDisplaysP ower P ower suppliessuppliesCablesCablesKeyboardsKeyboardsP rintersP rintersM ouseM ouse etcetc.. areare allall HardwareHardware



S oftwareS oftware

SoftwareSoftware refersrefers toto partsparts of of thethe computer computer whichwhichdodo notnot havehave aa materialmaterial form,form, suchsuch asas programs,programs,data,data, protocols,protocols, etcetc..WhenWhen softwaresoftware isis storedstored inin hardwarehardware thatthat cannotcannoteasilyeasily bebe modifiedmodified (such(such asas BIOSBIOS RO MRO M inin ananIBMIBM P CP C compatible),compatible), it it isis sometimessometimes calledcalled"firmware""firmware" toto indicateindicate thatthat itit fallsfalls intointo ananuncertainuncertain areaarea somewheresomewhere betweenbetween hardwarehardwareandand softwaresoftware. .



Appli c ationAppli c ation softwaresoftware performsperforms specificspecifictaskstasks or or applicationsapplications

Sy stemsSy stems softwaresoftware allowsallows aa computer computer totooperateoperate andand runrun applicationapplication softwaresoftware. .



User InterfaceUser Interface

Graphical user interface (GUI)Graphical user interface (GUI)M icrosoft WindowsM icrosoft Windows

Text user interfaceText user interfaceCommand line interface, shellsCommand line interface, shells



Arithmeti c/L ogi c Unit ( ALU)Arithmeti c/L ogi c Unit ( ALU)

TheThe ALUALU isis capablecapable of of performingperforming twotwoclassesclasses of of operationsoperations: :

ArithmeticArithmetic andandLogicLogic



AnAn ALUALU maymay alsoalso comparecompare numbersnumbers andand returnreturn

BooleanBoolean truthtruth valuesvalues (true(true or or false)false) dependingdependingonon whether whether oneone isis equalequal to,to, greater greater thanthan or or lesslessthanthan thethe other other ("is("is 6464 greater greater thanthan 6565?")?")LogicLogic operationsoperations involveinvolve BooleanBoolean logiclogic:: AND,AND,OR,OR, XORXOR andand NOTNOT.. TheseThese cancan bebe usefuluseful bothbothfor for creatingcreating complicatedcomplicated conditionalconditional statementsstatementsandand processingprocessing BooleanBoolean logiclogic..



M emor yM emor yAA computer'scomputer's memorymemory cancan bebe viewedviewed asas aa listlist of of cellscells intointo whichwhich numbersnumbers cancan bebe placedplaced or or readread. .

Computer Computer mainmain memorymemory comescomes inin twotwo principalprincipalvarietiesvarieties: :

RandomRandom AccessAccess M emoryM emory or or RA MRAM

ReadRead- -onlyonly M emoryM emory or or RO MRO M

RAMRAM cancan bebe readread andand writtenwritten toto anytimeanytime thethe C P UCP Ucommandscommands it, it, butbut RO MRO M isis prepre--loadedloaded withwith datadata andandsoftwaresoftware thatthat never never changes,changes, soso thethe C P UCP U cancan onlyonlyreadread fromfrom itit..



M emor y««.M emor y««.RO MRO M isis typicallytypically usedused toto storestore thethe computer'scomputer's initialinitial startstart--upup instructionsinstructions. . InIn general,general, thethe contentscontents of of RA MRAM areareerasederased whenwhen thethe power power toto thethe computer computer isis turnedturned off off whilewhile RO MRO M retainsretains itsits datadata indefinitelyindefinitelyInIn aa P C,P C, thethe RO MRO M containscontains a a specializedspecialized programprogram calledcalledthethe BIOSBIOS thatthat organizeorganize loadingloading thethe computer'scomputer's operatingoperatingsystemsystem fromfrom thethe hardhard diskdisk drivedrive intointo RA MRAM whenever whenever thethecomputer computer isis turnedturned onon or or resetreset. .SoftwareSoftware thatthat isis storedstored inin RO MRO M isis oftenoften calledcalled firmwarefirmwarebecausebecause it it isis theoreticallytheoretically moremore likelike hardwarehardware thanthansoftwaresoftware



M emor y««.M emor y««.

FlashFlash memorymemory blursblurs thethe distinctiondistinctionbetweenbetween RO MRO M andand RA MRAM byby retainingretaining datadatawhenwhen turnedturned off off butbut beingbeing rewritablerewritable likelikeRAMRAM ..However,However, flashflash memorymemory isis typicallytypically muchmuchslower slower thanthan conventionalconventional RO MRO M andand RA MRAM

soso itsits useuse isis restrictedrestricted toto applicationsapplicationswherewhere highhigh speedsspeeds areare notnot requiredrequired. .



Input /output ( I/O )Input /output ( I/O )HardHard disksdisks areare commoncommon I/OI/O devicesdevices usedused withwith computerscomputersI/OI/O isis thethe meansmeans byby whichwhich aa computer computer receivesreceives informationinformation fromfrom thetheoutsideoutside worldworld andand sendssends resultsresults backbackDevicesDevices thatthat provideprovide inputinput or or outputoutput toto thethe computer computer areare calledcalledperipheralsperipherals. . OnOn aa typicaltypical personalpersonal computer,computer, peripheralsperipherals includeincludeinputinput devicesdevices likelike thethe keyboardkeyboard andand mouse,mouse, andand outputoutput devicesdevices suchsuchasas thethe displaydisplay andand printer printer. .HardHard diskdisk drives,drives, floppyfloppy diskdisk drivesdrives andand opticaloptical discdisc drivesdrives serveserve asasbothboth inputinput andand outputoutput devicesdevices. . Computer Computer networkingnetworking isis another another formformof of I/OI/O..Often,Often, I/OI/O devicesdevices areare complexcomplex computerscomputers inin their their ownown rightright withwith

their their ownown CP

UCP

U andand memorymemory. . AA graphicsgraphics processingprocessing unitunit mightmightcontaincontain fiftyfifty or or moremore tinytiny computerscomputers thatthat performperform thethe calculationscalculationsnecessarynecessary to to displaydisplay 33DD graphicsgraphics. . M odernM odern desktopdesktop computerscomputerscontaincontain manymany smaller smaller computerscomputers thatthat assistassist thethe mainmain C P UCP U ininperformingperforming I/OI/O



M ultitaskingM ultitaskingWhileWhile aa computer computer maymay bebe viewedviewed asas runningrunning oneonegiganticgigantic programprogram storedstored inin itsits mainmain memory,memory, inin somesomesystemssystems it it isis necessarynecessary to to givegive thethe appearanceappearance of of runningrunning severalseveral programsprograms simultaneouslysimultaneouslyThisThis isis achievedachieved byby havinghaving thethe computer computer switchswitch rapidlyrapidlybetweenbetween runningrunning eacheach programprogram inin turnturnOneOne meansmeans byby whichwhich thisthis isis donedone isis withwith aa specialspecial signalsignalcalledcalled anan ³interrupt´³interrupt´ whichwhich cancan periodicallyperiodically causecause thethecomputer computer toto stopstop executingexecuting instructionsinstructions wherewhere itit waswas andanddodo somethingsomething elseelse insteadinsteadByBy rememberingremembering wherewhere itit waswas executingexecuting prior prior toto thetheinterrupt,interrupt, thethe computer computer cancan returnreturn toto thatthat tasktask later later



M ultitasking ««M ultitasking ««If If severalseveral programsprograms areare runningrunning "at"at thethe samesame time",time", thenthenthethe interruptinterrupt generator generator mightmight bebe causingcausing severalseveral hundredhundredinterruptsinterrupts per per second,second, causingcausing a a programprogram switchswitch eacheachtimetime..SinceSince modernmodern computerscomputers typicallytypically executeexecute instructionsinstructionsseveralseveral ordersorders of of magnitudemagnitude faster faster thanthan humanhumanperception,perception, it it maymay appear appear thatthat manymany programsprograms arearerunningrunning atat thethe samesame timetime eveneven thoughthough onlyonly oneone isis ever ever executingexecuting inin anyany givengiven instantinstant. .ThisThis methodmethod of of multitaskingmultitasking isis sometimessometimes termedtermed "time"time--sharing"sharing" sincesince eacheach programprogram isis allocatedallocated a a "slice""slice" of of timetimeinin turnturn



M ultipro c essingM ultipro c essingCrayCray designeddesigned manymany supercomputerssupercomputers thatthat usedusedmultiprocessingmultiprocessing heavilyheavilySomeSome computerscomputers maymay dividedivide their their workwork betweenbetween oneone or or moremore separateseparate C P Us,CP Us, creatingcreating a a multiprocessingmultiprocessing

configurationconfigurationTraditionally,Traditionally, thisthis techniquetechnique waswas utilizedutilized onlyonly inin largelarge andandpowerfulpowerful computerscomputers suchsuch asas supercomputers,supercomputers, mainframemainframecomputerscomputers andand serversserversHowever,However, multiprocessor multiprocessor andand multimulti--corecore (multiple(multiple C P UsCP Usonon aa singlesingle integratedintegrated circuit)circuit) personalpersonal andand laptoplaptopcomputerscomputers havehave becomebecome widelywidely availableavailable andand arearebeginningbeginning toto seesee increasedincreased usageusage inin lower lower--endend marketsmarketsasas aa resultresult. .



M ultipro c essing ««M ultipro c essing ««SupercomputersSupercomputers in in particular particular oftenoften havehave highlyhighly uniqueuniquearchitecturesarchitectures thatthat differ differ significantlysignificantly fromfrom thethe basicbasicstoredstored- -programprogram architecturearchitecture andand fromfrom generalgeneral purposepurposecomputerscomputers. .

TheyThey oftenoften featurefeature thousandsthousands of of CP

Us,CP

Us, customizedcustomized highhigh--speedspeed interconnects,interconnects, andand specializedspecialized computingcomputinghardwarehardware. .SuchSuch designsdesigns tendtend toto bebe usefuluseful onlyonly for for specializedspecialized taskstasksduedue toto thethe largelarge scalescale of of programprogram organizationorganization requiredrequiredtoto successfullysuccessfully utilizeutilize mostmost of of aa thethe availableavailable resourcesresourcesatat onceonce. .SupercomputersSupercomputers usuallyusually seesee usageusage inin largelarge--scalescalesimulation,simulation, graphicsgraphics rendering,rendering, andand cryptographycryptographyapplicationsapplications



Networking & InternetNetworking & Internet



NETW ORK ING DEVI CE S

Topology of a LAN means its physical layout. There are three main types of Network Topology, namelyBus Topology,Star Topology and

Ring Topology.



N etworking Devi c es

HubsThese provide central connection point for aLAN. They organize cables and relay datasignals to all computers. There are ports onthe back of a hub used to connect computers.They come in different sizes and shapes.



RepeatersRepeaters regenerate signals. A repeater would amplify the entireelectric signal it receives. However, it has no capabilities of directing network traffic.

B ridgesA Bridge is a combination of hardware and software. It has its ownoperating system. It helps to conserve the bandwidth of a network.Bandwidth is the speed of a network. It indicates how many bitscan be transmitted across a network in a given time.

In case of a bridge, the larger network is physically chopped intosmaller segments. A bridge can read the M AC ( M edia AccessControl) or physical address of a computer on data packets. M ACaddress is printed on the Network Interface Card.A bridge matches this M AC address with the one stored in itstable and judges that which particular segment does a data packetbelong to and accordingly sends that packet to such a segment.It does not allow other packets belonging to other segments tospread to a particular segment and hence conserves thebandwidth .



S wit c hesA switch is also a combination of hardware andsoftware having its own operating system. Likebridges, the switches are also used to increase thebandwidth of a network. However, in case of a switch,a network is virtually divided into small segmentscalled Virtual LANs or VLANs.

Similar type of users can be grouped into a VLANdespite that they have no physical proximity or closeness. A switch would read the M AC address ona data packet and match it with the list of M ACaddresses of the user machines contained in it.

It then sends data packets only to that machine on aVLAN to which these packets relate. P acketsbelonging to other VLANs are not allowed to enter into a particular VLAN, hence bandwidth increases.



RoutersRouters use a combination of hardware and softwareto forward data packets to their destination on the

internet. They are more efficient and sophisticatedthan bridges and switches.They can divide large networks into logical segmentscalled Subnets on the basis of I P addressing scheme.A router can communicate with another router on the

internet with the help of Routing InformationP

rotocol,and thus it can build a routing table. This routing tablecontains information about different networkaddresses and different routes for delivery of datapackets to a host machine on a network.A router is a decision making device. When a datapacket arrives at a router it reads the networkaddresses from the I P address on the data packetand determines the shortest possible path throughwhich this packet can be delivered to its destination.



Following diagram explains howrouters on the internet backboneforward data packets bydetermining the shortest possiblepath for the destination.In this example a client machineµA¶ sitting on network no. 140.57sends data to a web server µB¶hosted at network no. 100.µR1¶ is the router attached tonetwork no. 140.57. After consulting its routing table it can

find that the shortest possible pathfor sending data to machine µB¶ isto forward data packets to µR2¶,the router attached to network no.100.In case there is a blockadethenµR1¶ can look for thealternative shortest path.Here, the alternative shortest pathfor the delivery of data packets toµB¶ can be R1-R3-R4-R2.



� The Internet is a worldwide computer network.

� It is a network of networks.

� There is no central control, all the computers and sub-networksare linked together on a voluntary basis.

�These computers use the TCP/IP (Transmission Control

Protocol/Internet Protocol) as the method of connecting to eachother and transferring information.

What is the Internet?



Ex ample«What is the Internet?

LAN Server Fire all

Router

Router

Router

Telecomonnection

Telecomonnection

LAN sends a request out on the Internet to a "remote" net ork...

LAN

Remote LAN



How the Internet WorksHow the Internet Works

IPIP ddressddressBecauseBecause thethe internetinternet isis aa network,network, eacheachcomputercomputer mustmust havehave aa uniqueunique addressaddress justjust likelikeanyany nodenode onon aa network network ..

E veryE very ComputerComputer hashas anan IPIP addressaddress ,, thatthat isis

uniqueunique; ; forfor exampleexample thethe IPIP addressaddress of of CSUSCSUS. .eduedu isis 130130..8686..9090..11



How the Internet Works (cont..)How the Internet Works (cont..)

W henW hen thethe requestrequest isis issuedissued itit firstfirst goesgoes toto aaserverserver thatthat determinesdetermines thethe addressaddress of of thetheremoteremote serverserverThenThen itit goesgoes toto aa router router thatthat ³routes´³routes´ it it totothethe destinationdestination. .W ithW ith VisualVisual outeoute youyou cancan seesee thethe routersrouters

implicatedimplicated andand theirtheir placeplace inin thethe worldworld



Security is the biggest factor slowing downthe growth of e-commerce worldwide. For instance, when you enter your credit cardno. in a text box, it is potentially exposedto millions of people on the internet andcan be misused. It is important to know

following terms in connection with thesecurity threats over the internet

S e c urit y Issues over the Internet



B a c k Doors and T rojan Horses

Back Doors are those hostile programs which, when runon a machine, install hidden services in order to giveattackers remote access capabilities to a compromisedmachine.

Trojan horses are those programs that appear harmlessbut actually have some malicious purpose. For example,HAPPY 99.EXE is a Trojan horse that displays a fireworkand then sends copies of it to the e-mail addressesfound on the system.The term Trojan Horse has been borrowed from history.In history it has been used to refer to a huge woodenhorse where the whole Greek army was hidden during awar and the enemy was deceived because it could notfigure out that.



V iruses and W ormsViruses and Worms are malicious programs that cantravel between computers as attachments on email or independently over a network. These terms aresometimes used interchangeably; however, essentiallythey are different.Worms spread from computer to computer, but unlikeviruses have the capability to travel without any help or human action. A worm can replicate itself which meansthat it can send copies of itself to everyone listed in the email address box on a system.Viruses, on the other hand, need to be activated througha human action.Another difference is that viruses modify existingprograms on a computer unlike worms which can installback doors or drop viruses on the system they visit.



F IREW ALLS

A firewall is a combination of hardwareand software that sits between the internetand internal network of an organization toprotect the network from outside attackIt can examine the data entering or leavingfrom the network and can filter the dataaccording to certain rules, thus, protectsthe network from an attack.



P rox y S erver

A proxy server sitsbetween an internaltrusted network and

the un-trustednetwork, that is,internet



E- B usiness

An e-business is defined as a company/entitythat has an online presence.E-businesses that have the ability to sell, trade,barter or transact over the web can beconsidered as e-commerce businesses.An e-business model is defined by a company¶spolicy, operations, technology and ideology.



Advantages of E- business

P ersonalized serviceHigh-quality customer serviceNo inventory costWorldwide reach of the businessElectronic catalogues (convenient andquick transaction)Bulk transactionsImproved supply chain management



Disadvantages of E- business

Less se c urit yLess priva cy

N o ph ysi c al proximit y with itemspur c hased



Online c atalogues vs . P aper c atalogues

P aper c atalogsAdvantages

Easy to create a catalog without high technologyReader is able to look at the catalog withoutcomputer systemM ore portable than electronic catalog

DisadvantagesDifficult to update changes in the productinformationOnly limited number of products can be displayed



Online or E le c troni c Catalogs

AdvantagesEasy to update product informationAble to integrate with the purchasing process

Good search and comparison capabilitiesAble to provide timely, up-to-date product informationCan provide broad range of product informationP ossibility of adding voice and motion picturesCost savingsEasy to customize



Disadvantages

Difficult to develop cataloguesLarge fixed cost if used for small no. of productsNeed for customer skill to deal with computersand browsers

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