According to the Missouri Department of Health & Senior Services, the difference between the two is not huge. Both terms refer to a type of living arrangement for seniors that is more home-like as compared to institutions like nursing homes.
Residential Care Facilities (RCF's)
These are usually smaller than Assisted Living facilities, and could be as small as a private home that has been converted to include living spaces for elderly residents. The license requirements state that facility must provide for at least three residents. It also states that the care must include room and board.
There are two levels of Residential Care Facilities: The first level provides the least care, and does not require that a professional licensed Nursing Home Administrator be part of the management. The higher level does require a licensed Nursing Home Administrator, and allows for supervision of medical care under the direction of a licensed physician.
Both levels require residents to have the capability to "make a path to safety unassisted" in the event of an emergency. This provision obviously refers to the resident's mobility and whether they are able to walk on their own.
Assisted Living Facilities
These larger residences can provide more care than you would typically find in a RCF. Beside shelter and board, they can provide "assistance with activities of daily living which include eating, dressing, bathing, toileting, transferring and walking." They are supposed to offer what's called a "social model of care", which is not clearly defined in the regulations. In our opinion, we think this refers to non-medical activities that improve the standard of living like hobbies, special interests, and entertainment.
Unlike the RCF's, these facilities can accept patients who would need assistance in vacating the facility during an emergency. The regulations state that it must be "minimal assistance".
Getting More Information
If you have questions, be sure to discuss them with the facility's management. Each of the passages above in quotation marks come from the Missouri Department of Health & Senior Services web page called Level of Licensure for Long Term Care Facilities