What you have to forgo if you choose to do A rather than B; the value of the next best alternative that is foregone whenever a choice is made.
People’s spoken recollections of the past, sometimes recorded through an audio or video interview.
A map that only gives very basic information so that more detail can be added, for example, a map showing borders of a country.
As described in the Australian Curriculum: History, an overview provides a conceptual and chronological framework for understanding a particular historical period. It can consist of key features, events, developments and broad patterns of historical change. An overview provides a context for a depth study.