Basic Consepts of IT

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ICDL International Computer Driving License.

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Basic Concepts Of Information Technology (IT)

The Basics –What is Information? : 

The Basics –What is Information? Information is data processed for some purpose Information can only be considered to be 'real' Info if it meets certain criteria i.e. 1.it must be communicated to the recipient 2.it must be in a language that is understood 3.it must be in a suitable form 4.it must be relevant for achieving some purpose

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Information Information is any form of communication that provides understandable and useful knowledge for the person receiving it.

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What Is A Computer? A computer is a general purpose, programmable device that is used for the production and processing of information capable of calculating and storing results

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What do we mean by general purpose? Most devices can be described by their function e.g. Washing Machine, DVD Player Computers, however, can be used for almost any purpose: -typewriter -video editor -accounts tracker -database / address book -DVD / CD Player -and many others

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Computers Are Programmable Computers respond to instructions in the form of programs Programs are written in order to make computers behave in specific ways i.e. word processor, systems control Programs are stored in the Computer memory

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How computers process information Computers accept inputs ( i.e. data) The input is translated into binary numbers and ‘processed’ The process produces output (i.e information) This sequence can repeat endlessly: outputs can be inputs!

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Processing -the ‘Black Box' model We can think of a computer as a ‘black box’:

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Components of a Computer System Computer Systems are made up of: Hardware –the physical parts Software -the instructions or programs that control the hardware The Human Being –the brains behind the whole system

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Types Of Computer Mainframe Computer Minicomputer Personal Computer (Microcomputer / Desktop) Laptop Network Computer / Server –Uses two types of terminal: “Dumb”and “Intelligent”

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Types Of Computer Main Frame Computer Mini Computer PC – Personal Computer Laptop Network Computer

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Computer Organisation –the Von Neumann model Most Computers are based on a model proposed by John Von Neumann in 1946 The ‘logical' units of this model are: –Stored program –Central Processing Unit: fetches and executes the program instructions sequentially –Memory –Input and Output devices

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Computer Hardware components A typical PC System is made up of: –System Unit –Keyboard –Monitor (VDU) –Mouse –Printer –Modem –Multimedia Devices

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Hardware –The System Unit The central component of the system Houses: –The Processor: corresponds to the CPU –Memory: RAM and ROM –Storage: Hard Disk, Removable Storage devices

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The Processor (CPU) Types include Intel Pentium series, Celerion, AMD Athlon Chip at the heart of the computer-does the calculations Speed is very important –measured in megahertz (MHz): the faster the processor the more calculations performed per second.

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Memory A computer must be able to store its calculations and programs Two types of memory: “Volatile "and permanent. Measured in bytes One byte = eight bits

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Random Access Memory (RAM) Used by the Computer as the working area Holds the working program, the data being processed and the interim results Volatile -contents are erased if power is cut Can be accessed randomly: can get any piece of data directly. Faster than permanent storage Not to be confused with ROM (Read-Only Memory)

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Storage -Hard Disk Permanent Memory -records and stores all programs and data / information magnetically Larger than RAM -average 12 -120GB Slower -involves mechanical movement (read/write head, revolving disk)

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Other types of Storage Floppy Disks CD/DVD ROM Zip Drive Magnetic Tape

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Input Devices Keyboard Mouse: used in conjunction with the GUI (Graphical User Interface), point and click Other types of Input Devices: –Trackballs –Light Pens –Touch Screens –Tables

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Output Devices Monitor: also known as the Visual Display Unit (VDU) Printers –Laser Printer –Inkjet Printer –Impact

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Software Generic name of all programs Made up of code interpreted by the hardware Written in programming languages -Java, C, C++, Perl Two kinds of Software: –System –Application

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System Software Concerned with the computer itself: devices, file and storage management, error correction Main piece of SS: Operating System (OS) OS: the driving program of the computer –communicates between all programs and the hardware –controls timing and sequence of events –manages data to ensure security and integrity –Examples: Windows, Mac OS, Unix

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Applications Software Concerned with the world outside the computer Gives the computer its general purpose nature Used for the things you want the computer to do Common Examples -Word, Excel, Internet Explorer Applications can be more specialized: e.g. Architecture package

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How Software is made Involves a cycle of research, analysis, development and testing Systems Analysts -study the business processes and designs the software Programmers -develops the software

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Problems with Software Software is complex Difficult to test comprehensively Can have bugs: these can be trivial or major Symptoms of bugs –hanging –crashes

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The Graphical User Interface (GUI) Represents all the program / computer resources as icons Workspace represented graphically -creates ‘virtual' documents More usable: led to wider use of computers Adds to the unique nature of the computer as both a tool and a medium

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Do’s and Don’t’s DO give the computer room to breathe keep it in a dry place dust free shut down properly keep removable storage away from the screen DON’T block air vents eat or drink while using the computer expose to extremes of temperature just switch off move while the computer is in operation

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Thank you.