Database chp9 (finished)

Database chp9 (finished)

1. Data: facts and statistics collected together for reference or analysis

   • different types of data
     • 1.audio
     • 2. video
     • 3.images
     • 4. text

2. Devices / Components: Used as a generic term to mean computers

   • examples
     • mobile telephones
     • manufacturing plant
     • environment monitors
     • peripheral hardware
       • (Any device, such as a printer, attached to a computer to expand its functionality)

3. Voice over Internet Protocol : hardware and software that enables people to use the Internet as the transmission medium for telephone calls

   • hardware needed
     • microphone input
     • speakers
     • headphone output
     • broadband
   • VOIP is used for
     • Web meetings
     • Conferences
     • talking to friends and family
   • examples of VOIP systems
     • Skype
     • facetime
     • facebook messanger

4. Codec: a device or program that compresses data to enable faster transmission and decompresses received data.

5. Wireless network:A network servicing computers which the connections do not use cables

   • what you need to set up a wireless network
     • Routers
     • network access points
     • computers
   • one advantage of using wifi is mobilty, you dont need to stay at the same place for it to work

6. other connection methods

   • UTP/ STP: Unshielded twisted pair (UTP) cables are basic pairs of cablest twisted together. Shielded twisted pair (STP) cables are similar but have a foil shielding.
     • used in Analogue telephone network
     • Benefit: low cost and adaptable
     • Disadvantage: slower and less capably than other cables
   • Coaxial: Solid wire core separated from a copper-braided outer cable by a plastic insulation sheath. The inner cable transmits the data and the outer cable connects to earth.
     • used in Aerial/dish connection to TV.
     • Benefit: fast and reliable
     • Disadvantage: costs more than UTP/STP
   • infred:Short range data transmissions using infrared light
     • used in Keyboard, printer, mouse to processor unit.
     • Benefit: tends to be reliable
     • Disadvantage: short range
   • Microwave: Short wavelength radio transmissions working at very high frequencies.
     • used in bluetooth
     • Benefit: signal degrades very little over long distance
     • Disadvantage: devices must be in direct line of sight
   • Satellite: Data is transmitted from Earth to a satellite, whichrelays it to the relevant receiving station back on earth.
     • used in Global communication systems
     • Benefit: increases the distance that a network can stretch
     • Disadvantage: expensive