The History of Doors

https://en.wikipedia.org/wiki/Door Source

You know what this is, how to use it, everybody knows it. Doors.

Doors such as house doors and gates (which are a type of door), use locks, as a way to deter people from entering or accessing the areas blocked by a said door. Pivoting off a metal hinge, the door in question could rotate up (such as the Tesla Cars from Tesla) or to the side. 

As doors were a major part of history, it was a greatly used piece of literature as it meant Methopraical meaning for change. And doors have a variety of aesthetic, symbolic, and ritualistic meanings. 

Now the history

The earliest telling of doors is that it was mentioned in Egyptian tombs, generally shown as double or singular doors.

As most of the ancient doors were made from timber wood. The Romans and the Greeks used different kinds of doors, singular doors, double doors, or even triple doors.

As we are coming to the modern era, we still have the "doors of old" meaning doors from centuries ago, and they are still used today and used in places of worship in Religious buildings and old structures built long ago.

As we are coming to the modern era, we now use automatic doors often.

If you walk through one, maybe as an entry to a long hall, but as a gateway to a multitude of possibilities, but hey, we all gotta walk through one eventually.