The split_string_into_string_list_by_regular_expression parses the string 'a,b,c,d,e' and outputs the list ['a','b','c','d','e']. The choose service displays a dialog with 'Some title' and with 'Some message'. The user is able to choose from the values ['a','b','c','d',e']. When the user presses OK the value the user chose is passed to the answer port of the choose service and so to the output of the workflow.