The goal of the workflow is to demonstrate the creation and working with collection cells. It is divided into three parts. The "Collection creation and conversion" part shows how collection columns can be generated by combining rows e.g. by grouping them in the GroupBy node or columns e.g. by combining them in the Column Aggregator node. The "Collection types" section describes the two different collection types that are supported by KNIME namely Lists: list all elements including duplicates in the order they were added to the collection. Sets: list the elements in an arbitrary order but contain each element only once. The last section "Working with collections" demonstrates a sub set of the nodes that support collections such as the Item Set Finder (Borgelt) node which searches in a collection column for frequently co-occuring elements.
This is a companion discussion topic for the original entry at https://kni.me/w/V5cKM7KicPYqiG3A