This is a generic term covering all the activities around normal life 1) from the period in question.
What we do is bring along several replicas of period items and use them to show what life was like. We try our best to use period foodstuffs and techniques to feed ourselves, using period implements and just generally get a little under the skin of how life was.
Our range of activities covers military encampments, taking over small houses, running church courts and poor sessions, and other scripted pieces. During all of this we engage the public in what we do, either involving them as juries in the courts or by explaining what we are doing and why, using a technique appropriate to the level of immersion that the sponsor is looking for.
The pictures below demonstrate this better than text does. Click on the thumbnail to see the full size image (currently the thumbnails are not rendering properly on my system, but viewable in full-size OK).