This semester, we talked a lot about Goffman's concepts of frontstage and backstage. One of the things that struck me about it is that it is, as so many other concepts, fractal. You can apply it to just about any level, and then move either upwards or downwards, finding roughly the same processes going on. The scales differ, but the process remains the same.
These words have the advantage of meaning what you think they mean. Backstage is the social space behind the stage, where the last-minute rehearsals, costume changes and informal banter takes place, while frontstage is, well, on stage. The two spaces have different social dynamics, and things that are proper in one is improper in the other, and vice versa. While the play is on, only the actors who are supposed to be on stage are on stage, and they have very defined roles to play; the show must go on. Only when they have retreated backstage can the actors let their guard down, stop acting and - quite unceremoniously - collapse into the post-performance heaps they really are.
The audience members, too, have roles to fill whilst the show is on. The fact that these roles mostly consist of sitting and watching makes them comparatively easy to play; this does not, however, take away from the fact that things get very strange very fast if audience members suddenly decide to join in on the action. Everyone present have roles to fill, and most everyone present know these roles implicitly.
A non-theatrical example is a restaurant. Out among the tables, things are quiet and posh, with hushed conversations taking place among the dining guests, a reprieve from the hustle and bustle of everyday life. In the kitchen, however, the hustle and bustle is in full swing, with yelling, fast-paced motions and a stress level that is through the roof. The difference between frontstage and backstage is not subtle.
The fact that these two states of things happen in close proximity to each other means that there have to be boundaries between them. Often enough, these boundaries are subtle until you try to cross them. A restaurant guest is usually not allowed into the kitchen, and quickly escorted out should they somehow stumble into it. Shoppers are allowed to browse the store area, but any attempt to enter the back rooms will be ever so efficiently discouraged. If you do not have a keycard, you are not allowed into the office building. At concerts, only those with backstage passes are allowed into these mystical spaces.
Most spaces can be analyzed using these concepts. They are very versatile in this regard.
They are also fractal. Individuals act differently when they are frontstage (often quite literally meaning that they are not alone) than when they are backstage, and the boundaries between these states allow very few persons access. A small group (beginning at two persons) can similarly act differently when in a frontstage setting than when alone, with similar boundaries to entry. A large group (a theatre production, for instance) can project a particular image frontstage, while having very different dynamics backstage. And so on, scaling up as much as need be. (I suspect the discovery of alien life will have interesting implications in this regard.)
The only thing needed to use these concepts is an impulse to apply them to concrete situations. Upon reading this, you now have this impulse.