I am by no means an expert on the subject, but cohousing is a residential type in which each member will own their living unit as well as a share in a common areas. Many times these common areas will include a garden or greenhouse, a large kitchen and dining room, social spaces, and a yard. The purpose behind this is to minimize individual ownership of public areas and thereby expense, and emphasize community activity. This has positive psychological effects and is considered much more socially sustainable than more typical housing types.
The Pioneer Valley Cohousing website explains it like this:
"Cohousing is a Danish concept that came to the US in the late 1980s and is quickly gaining momentum across the country. Members own individual homes and maintain their privacy and autonomy while sharing some meals, activities, facilities and, most important, a community spirit."
Hope this helps!
It does. Thank you!