Data Representation

Data Representation

1. Data storage units

   • Bit
     • 1 or 0
   • nybble
     • 4 bits
   • byte
     • 8 bits
   • kilobyte
     • 1024 bytes
   • megabyte
     • 1024 kilobytes
   • gigabyte
     • 1024 megabytes
   • terabyte
     • 1024 gigabytes
   • petabyte
     • 1024 terabytes
   • exabyte
     • 1024 petabytes
   • zettabyte
     • 1024 exabytes
   • denary

2. Number systems

   • denary
     • binary
     • hexadecimal
   • binary
     • hexadecimal
     • denary
   • hexadecimal
     • denary
     • binary

3. why does data have to be converted into binary

   • binary numbers representing characters
   • data types such as integer, character and string
   • hexadecimal numbers representing binary numbers
   • the terms 'character set'. Unicode and American Standard Code for Information Interchange (ASCII)
   • truth tables and logical operations: AND and OR and NOT

4. how computers interpret instructions

   • how instructions are coded as bit patterns
   • how the computer knows if it is reading instructions or data
   • how sound can be sampled and stored digitally
   • how an image is represented by pixels in binary form
   • why metadata needs to be included in an image file (including height, width, color and depth)