Definitions of contribution:

• noun:   any one of a number of individual efforts in a common endeavor

  Example: "I am proud of my contribution to the team's success"

• noun:   act of giving in common with others for a common purpose especially to a charity
• noun:   a writing for publication especially one of a collection of writings as an article or story
• noun:   an amount of money contributed

  Example: "He expected his contribution to be repaid with interest"

• noun:   a voluntary gift (as of money or service or ideas) made to some worthwhile cause