This set of teaching notes provides extensive guidance for educators related to its sister title and contains numerous tools and questions to help educators provide didactics and evaluation of students in this essential area of biomedical informatics.  This is needed to understand the central topics of ontology, terminology and terminological systems in healthcare. Twenty-five years ago the notion that ontology would be essential to knowledge representation in healthcare was all but unknown. Almost all important terminologies and many ontologies are now in wide use and are growing in importance. With no general model of what a ontology and terminology should be, there are an increasing number of tools to support ontology / terminology development, implementation and maintenance. Steady progress since then has improved both ontology / terminology content and the technology and processes used to sustain that conte  .