The names of various senior housing alternatives can be confusing. Here are a couple of different forms:
Active Adult: Those many, many communities which have sprung up all over the country offering single family homes with many amenities. There are no provisions for medical assistance other than what the resident arranges on his/her own. This would be like Rossmoor in Walnut Creek.
Independent Living: A separate unit which may or may not have a kitchen, and residents take their meals together in a common dining room. These can be actual real estate like condos at the Waterford in Rossmoor or rentals in a myriad of projects located all over the Bay Area.
Assisted Living: A facility where minor medical and hygiene needs can be tended to by staff. This could include memory care units.
Skilled Nursing Facilities: These are hospital like arrangements with doctors and nurses on staff usually 24/7.