What is a computer ?Definition:A Computer is a device that accepts input, processes data, andproduces an output according to a series of stored instructions. A computer is composed of hardware and software , and is available in different sizes and configuration
Data v/s InformationData refers to symbols that represent facts orideas…these really don’t mean anything untilthey are processed, or put in some sort ofcontext. Then they become information…sodata is raw and information is processed.
HardwareThe hardware is the part of the computer you can touch and see. e.g keyboard, monitor, disks, wires, chips, etc.
Hardware componentsINPUT DEVICES -- “How to tell what to do”Keyboards and mouse are the standard way to interactwith the computer. Other devices include joystick andgame pads(console) for gaming purpose.OUTPUT DEVICES – “How it shows you what it is doing”The monitor is how the computer send information back toyou. A printer is also an output device
Hardware componentsINPUT DEVICES• MOUSE -- small hand held device that attaches to thecomputer. It may have two or three buttons. The mouse isused to move the cursor (pointer) on the computer screen.• KEYBOARD-- what you type on, similar to a typewriter.• TRACKERBALL -- alternative to mouse , used by graphicdesigner• SCANNERS -- similar to a color photocopier is a device thatcaptures pictures or documents, so that they can be seen orused on the computer and many more like joystick, touchpad etc
Hardware componentsOUTPUT DEVICES• MONITOR/ VDU – It is the display screen, similar to atelevision screen• PRINTERS – It is a device that puts what you have createdon to a paper.• SPEAKERS – It enhances the value of educational andpresentation products. and many more like plotter , headphones etc
Hardware componentsSTORAGE DEVICES – “How it saves data and programs”•Hard disc drives – the internal higher capacity drive Speed- fast High capacity ( measured in gigabytes)•Floppy drives (diskettes) – Speed- very slow Very cheap Unreliable and low capacity ( 1.44 mb)
Hardware components•CD (compact disk) – Speed- slower than hard disk but faster than floppy disk (specifies in terms of 1x , 8x , 16x , 32x etc) Capacity – 750 MB•DVD (digital video disk) – Speed - faster than CD Capacity - 4.2 GB to 17 GB Cost - higher than CD•Pen Drive – Speed - faster than DVD Capacity – 1 GB to 16 GB
MemoryMemory – “how the processor stores and uses immediate data”• RAM (Random access memory) It is the main working memory of the computer When computer is turned on , operating system is copied into this memory only It is a volatile memory i.e data is lost as when computer is turned off More RAM means faster computer
Memory• ROM (Read only memory) It is a special type of memory chip that holds software which can be read but not written to. Often network cards and video cards also contain ROM chips
The Central Processing Unit• A CPU is on a chip called a microprocessor• It continuously follows the fetch-decode-execute cycle: Retrieve an instruction from main memory fetch execute decode Carry out the Determine what the instruction instruction is
The Central Processing Unit• The CPU contains: Performs calculations Arithmetic / Logic Unit and makes decisions Coordinates Control Unit processing steps Small storage Registers areas
USES OF COMPUTERPC @ HOME •Web browsing •Chat/ mail •Computer games •Banking from home etc……………PC @ OFFICE •Accounts •Payroll / Attendance •Presentations •Product designing etc…….