The topic of the present text is the interleaving distance of join trees by Morozov, Beketayev, and Weber (2013). Just like this paper we focus on topological data analysis (TDA), which is a broad field. What is interesting about join trees however, is that they provide for one of the most simple non-trivial approaches to topological data analysis. We use this as an excuse to motivate join trees through the role they play in this domain.