It is often advantageous for students to study in two areas in parallel. The Australian way of achieving this is different from the German approach. In Germany it has become common to combine two subjects into a single degree (e.g. Wirtschaftsingenieur).
This has the disadvantage that the student usually has to complete the degree in the same amount of time (and with the same number of lectures, etc.) as a student studying only one of these subjects. Obviously he will not learn as much about either subject as a German student just studying one of these (e.g. Wirtschaftswissenschaften or Ingenieurwissenschaften) as an individual subject.
In Australia (and other Anglo-Saxon countries) this is not the normal way of combining two areas of study. Instead the Australian student can often choose to study a combined degree course. This is possible both with bachelor degrees and with coursework master degrees.
A combined degree course consists of two degrees (which also exist as separate degrees) that are studied in parallel. The regulations for such a course usually allow the student to complete the combined degree in a shorter time than it would require for a student to study both degrees individually (without a loss of content). This is possible because the combined degree regulations usually take advantage of what are elective units and optional specialisations in the individual degrees, defining such electives as no longer optional. In this way, for example, it may be possible for a coursework master student to acquire two degrees in four semesters, although these would normally each require three semesters of study.