Making messages specific by sending additional information

• where, when, and with whom is a meeting?
• in which component should another appear?
  

Could write separate method for every possible combination of circumstances, but unwieldly and repetitive

Parameters allow us to generalize methods

who------>
when-----> Meet()
where------>
what is all this jargon?

Formal parameters are "dummy" variables that represent instances sent when calling method, for internal use only

• placeholders, like x in 2x+5
• have no value of their own; take on value of actual parameters passed in when method is called

Actual parameters are "actual" instances sent when calling method

• values passed with message from sender to receiver
• Method being called cannot know what specific instances will be passed to it, so must use a dummy name to represent each parameter
  
  
     
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