A [[sub-system]] often needs input data from you. A soil model might need precipitation data, a fruit model might need soil concentration data, etc. Sometimes this data can instead be provided by another sub-system. 

A [[block]] whose data can be provided by another sub-system is referred to as a model input. 

A [[connector]] allows you to connect each model input with a [[model output]] of another sub-system. 

====See also====

  * [[Model output]]
  * [[Connector]]
  * [[Sub-system]]