UML 2.0 in a Nutshell (In a Nutshell (OReilly))

10.7. Traces

UML defines a trace as a sequence of event occurrences. The term trace is used when discussing sets of event occurrences and how they may be combined. Interaction diagrams allow you to combine fragments in such a way that the event occurrences are interleaved. This combined set of event occurrences is considered a new trace.

Throughout this chapter we will refer to a sequence of event occurrences as event occurrences rather than as a trace to try and reduce the number of keywords.