What Is a Computer?

A computer is an electronic device, operating under the control of instructions stored in its own memory, that can accept data, process the data according to specified rules, produce results, and store the results for future use.

Data versus Information

Computers process data into information.

Data is a collection of unprocessed items, which can include text, numbers, images, audio, and video.

Information conveys meaning and is useful to people. One man's data is another man's information and vice versa. Example: one government agency produces information that is data to another agency, and so on.

Example: purchasing items in a store. Quantities and prices are input, processed (tallied up) and output to a paper receipt.

Information Processing Cycle

• Input
• Process
• Output
• Store

Components of a Computer

Computer hardware is the collection of physical elements that constitute a computer system.
Storage Capacities Table

• Input Devices any hardware component thta allows you to enter data and instructions into a computer
  • Keyboard
  • Mouse when the physical mouse moves a pointer or cursor on the screen moves.
  • Finger
  • Microphone
  • Scanner converts printed material, text and pictures to a form the computer can use
  • Web cam creates movies or pictures that are stored in the computer
• Output Devices any hardware component that conveys information to one or more people
  • Printer
  • Monitor
  • Speakers
• System Unit The computer case: a place to anchor the other parts of a computer
  • Motherboard
    • Processor CPU is the electronic component that intercepts and carries out basic instructions that operate the computer
    • Memory electronic components that store instructions waiting to be executed and data needed by those instructions 16GB Memory
    Most memory keeps data and instructions temporarily. Contents are erased when the computer is shut off.
• Storage Devices LOC unit
  The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits.
  Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures.
  
  • Storage holds data, instructions, and information for future use.
  • Example: Customer names and addresses
  • Storage is permanent
  • Storage media
    • USB flash drive
    • Hard disk Internal or External 4TB Drive
    • Optical Disk
      • CD 650 million to 1 billion characters
      • DVD 17 billion characters
      • Blu-ray 100 billion characters
    • Network Accessible Storage NAS
    • Cloud
• Communications Devices a hardware component that enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices. Ex: modem
  Communicate over:
  • Cables
  • Telephone Lines
  • Wireless
    • Cellular Radio Network
    • Satellite
    • Wifi
    • Bluetooth