Selecting family types and family instances in Revit using Dynamo could be a little confusing because the naming of nodes in Dynamo does not always make sense to the Revit UI user.
I have created a table and image of what the Dynamo family selection nodes and what they really mean and hopefully this will help you understand what they represent. Good Luck!
|Current Node Name||What they Represent|
|Family Types||Placeable Family Types|
|Element Types||System Family Categories|
|All Elements of Family Type||All Instances of Family Type|
|All Elements of Type||All Instances of System Family Category|
|All Elements of Category||All Instances of Category|
|What the Revit Selection Nodes Really Mean|
For those of you who want to hear the long version listen and watch this video where I explain this in more detail