Most people would say the current movement began with the so-called Arab Spring, although AFAIK the name "Occupy" did originate with the Wall Street group.

The literal, physical occupations are a way of saying tangibly that they aren't going away. But there are a lot of participants in the daily actions and General Assemblies who aren't staying the night.

It's an evolving movement, and *that* is the point. Organizers and facilitators are doing their best to ensure that the movement continues to evolve, and that specific goals and methods are chosen carefully. That can make it difficult to describe in sound bites, but that, I think is an illustration of the failure of modern media and of media consumers' attention spans, not of the movement.

Occupy Together is sort of a clearinghouse site and possibly a useful place to start to understand the movement. The best way to understand any local Occupation, obviously, is to attend a General Assembly or two, for anyone nearby.