units

• • Computers use binary numbers to represent data eg characters, images, sound
  • smallest unit of data - 1 binary digit aka 1 bit
  • 1 bit can only hold one value (2^1), this is not big enough to store all kinds of data -> different Units of Data
  • A unit of data is a term given to describe different amounts of binary digits stored on a digital device
• LABEL

  A) bit

  B) b

  C) 1

  D) 0

  E) nibble

  F) 4b

  G) byte

  H) B

  I) 8b

  J) character

  K) kilobyte

  L) KB

  M) 1000 B

  N) 10

  O) thousand

  P) text file

  Q) megabyte

  R) MB

  S) 1000 KB

  T) 20

  U) million

  V) music file

  W) gigabyte

  X) high efinition movie

  Y) terabyte

  Z) hard drive

  [) petabyte

  \) data centre

  
• Analogue data and digital data

  Analogue data is a real-life signal that can vary greatly in value. Examples include:

  • sound waves
  • pressure
  • temperature

  Digital data is binary data which represents analogue data. Computers work with digital data. Analogue data must be converted to digital before a computer can use it. A device known as an analogue-to-digital convertor (ADC) is used to generate digital data from analogue signals. In the same way, a digital signal can be converted back to an analogue signal using a digital-to-analogue convertor (DAC).
• Why does data have to be converted to binary to be processed by a computer?

  • A computer is built using switches that can either be on or off, this fits the binary number system which only has two digits (1/0), which means off can be represented by a 0 and on can be represented by a 1
  • This means all data must be converted to binary before a computer can understand and process it
  • Converting data to binary allows computers to process it at an incredible speed, perform complex calculations and store vast amounts of data efficiently
• • Data capacity is the maximum amount of information that a storage device can hold

  A) bytes per character

  B) number of characters

  C) resolution

  D) colour depth

  E) sample rate

  F) duration in seconds

  G) bit depth

  
• label

  A) 50

  B) 100

  C) 100

  D) 10