What is a computer?
• Electronic device
• Performs instructions in a program
• Performs four functions– Accepts data– Processes data– Outputs information– Stores results
A Few Terms
• Hardware – all the physical components
• Software – the operating system and programs
• Data – the raw facts the computer processes
• Information – data that has been organized
Input
• Everything entered into the computer– Data– Programs– Commands– User input – keystrokes, mouse clicks, joystick
buttons
Processing
• Similar to human’s thinking
• Execute complex tasks
• One simple step at a time
• Using bits and bytes of data
Processing components
• Microprocessor
• Motherboard
• Main Memory (RAM)
• Secondary Memory (Hard Drive)
• Operating System
• Application
The Power of a Computer
• Speed– System clock rate (i.e. 2.4 GHZ)– Bus width– Word size (32 bit; 64 bit)
• Reliability
• Storage– RAM (1 GB)
Storage
• The means of storing information/data for future use
• Main memory (RAM) - volatile
• Secondary memory – non volatile– Input (storing data and programs)– Output (storing processed data)
Storage Devices
• Optical– CDs– DVDs
• Flash– Memory cards– USB drives or thumb drive
• Smart cards and Optical cards
Types of Computers
• PC (personal computer)
• Desktop
• Tower
• Notebook or laptop
• Tablet PC
• Personal Digital Assistant (PDA)
• Workstation
Types of Computers
• Main frame
• Supercomputer
• Distributed or Grid Computing
• Server
• Mini-computer
Networking
• Transmission of data between two or more computers over a channel
• Communication channels– Network cable
– Coaxial
– Telephone lines
– Fiber optics
– Satellite transmission
– Microwave
– Wireless
Networking
• Signals– Analog – wave form
– Digital – stream of bits
• Modem– Translates analog into digital and the reverse
• Digital Modem– Connects one medium of transmission to connect to
another (i.e. coaxial to network cable)
Networks
• Share files
• Share printers and other peripherals
• Run programs remotely
• Local Area Network (LAN)
• Wide Area Network (WAN)
Network Communication
• Protocol– common language that allows devices to talk to
each other– Internet protocol (IP), file transfer protocol
(FTP), hypertext transfer protocol (FTP)
Software
• BIOS• Operating System• Utilities• Security• Applications
– Word processing– Spreadsheets– Games
Parts of a Computer
• On the front– Floppy drive– CD Rom Drive– CD Burner– DVD drive– Power button– Reset button– USB ports
Parts of a Computer
• Around the back– Power plug
– Fan
– PS/2 ports - keyboard/mouse
– Sound card ports
– Video card port
– Network Interface port
– Parallel Port
– USB Ports