Scenario ...
You are reading email from a friend in another country who complains that the temperature is 38o
The temp is Celsius, but what is it in Fahrenheit?
Why doesn’t your computer have a temperature converter?
This is a common situation -- there is some functionality that computers should have that the do not … the solution is to write a procedure
Application vs Procedure: The application is the entire facility (GUI + computation). The procedure is just the computation