noun (n)

• a unit of information equal to 1000 megabytes or 10^9 (1,000,000,000) bytes(noun.quantity)

  Synonym:
  g, gb
  

  source: wordnet30
• a unit of information equal to 1024 mebibytes or 2^30 (1,073,741,824) bytes(noun.quantity)

  Synonym:
  g, gb, gib, gibibyte
  

  source: wordnet30