Revit Family Selection Node Names in Dynamo are a little confusing. This is what they really represent...

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