Not all societies witness economic collapse or
recessions. The ones that do are too large and complex for any one person to fully understand. This is their biggest
vulnerability and this is the reason why collapse happens.
Economic collapse is what happens when the activities of a society which allow it to make a living cease to function. To meet the criteria for this definition it is not necessary that all activities that are economically related to cease, just enough so that generally people are no longer able to make a living in the usual manner.
A great and classic example here in the USA is the Great Depression. Renters became shantytown dwellers and farmers became migrant labor. In this case the industrial economy collapsed which lead to the growth of the rural economy.
It's important here for me to clarify what I mean by "economy". I mean all activity related to making a living, not exclusively buying and selling. I am counting the act of picking berries to eat out of hand as economic activity.
What happens during a collapse is that there is widespread agreement (even if begrudgingly) that the previous economic situation was not working out. Amongst those who benefited most from it there is a monumental effort to fix whatever went wrong to get their money making projects back on track. Amongst those who are shat out of the failure of that economic system to function there is a frantic searching for a way of life that works and will feed the family. Most often people turn to the ways of their ancestors and grow food and if they can afford them: animals for consumption and to sell. Many prostitute themselves to the remaining wealthy, others beg. Some migrate in search of remaining pockets of the old way of life where the collapse did not hit so hard. Some are so destitute that they enter a condition of slavery, that is a agreement of inescapable work trade for food and housing.
Always there is political turmoil, sometimes war. Some he-man senses an opportunity to grab for power and makes his moves. Or the poor revolt and demand those who are responsible for the crisis to be hanged and a reconstruction of society for benefit of the poor. In areas where an autonomous organization holds sway there may be moves to exploit the crisis for political independence.
The beneficiary of economic collapse is the natural world. No longer is there the intense pressure of resource exploitation as the previous resource intense lifestyle is no longer possible. In the short term, human survivors are reduced to a less intensive but not necessarily more sustainable way of living. The severity, duration of collapse and the extent of resource destruction prior to collapse will determine if it is even possible for the society to return to its pre-collapse state. If it cannot then perhaps, in its severely depleted environment, it will after many years rediscover a method for long living on its landbase.