Definitions of difference:

• noun:   the quality of being unlike or dissimilar

  Example: "There are many differences between jazz and rock"

• noun:   a significant change

  Example: "The difference in her is amazing"

• noun:   a disagreement or argument about something important

  Example: "There were irreconcilable differences"

• noun:   the number that remains after subtraction; the number that when added to the subtrahend gives the minuend
• noun:   a variation that deviates from the standard or norm