I've run into this one over and over. There will be some part of some application where the world will be represented with a tree as the data structure. Think hierarchies of various kinds - org structures, product catalogs, workspace groupings, etc.<p>The fact it's a tree is really important to the functionality the user wants, even if they don't know how to think in terms of trees in an abstract way ("you can roll up information from child orgs into their parent's reporting").<p>The language around trees just doesn't resonate and gets lost on people. This includes potential customers, sometimes project management, etc.<p>Have you ever come across a _really_ good way of describing trees? Or, in-context of requirements/work material, a means of talking about this idea that didn't cause people to lose focus?