Many people find the different types of senior living to be confusing. There are facilities called "independent living" which usually include an apartment in a building where residents do their own thing, but are provided meals, offered a beauty salon and various other services. Some of these services can be included in the basic fees while others can be added on. Examples might be someone to help with showers if a resident is not quite as steady as they used to be. Perhaps someone needs help remembering to take medication- someone might come by and remind you. There are many different services one can get in an independent living facility.
Facilities that call themselves "assisted living" can be very similar to independent living, however assisted living usually refers to a place where people need more assistance than above. These seniors usually have some medical issues and/or physical limitations; they made need help getting dressed, taking medications, getting around easily, and a variety of other possible needs.
Some facilities have different floors or sections specifically for residents who need extra assistance. In her final few years my mom lived in a facility that has 5 floors of independent living and one floor called AL or Assisted Living. The people on the AL floor have a variety of medical needs which are accounted for in different ways. For example the floor has a nursing staff available from 7:00am-10:00pm. In fact, many facilities have a nurse on staff 24/7. There are caregivers on this floor who help residents get dressed, use the bathroom, take medications, physically get around in wheelchairs, etc. There are very specific regulations about what types of residents can be cared for in an AL. This facility is not a nursing home and does not provide skilled nursing so they can't by law admit residents whose needs are greater than they can provide for.
Make sure when you are the one looking into care options for a loved one that you know exactly what care they need and what care is actually provided in different facilities. It is very common for facilities who provide AL to accept residents whose needs are greater than they can handle. They may feel like they can provide the care, but, according to the strict rules for each state, they may not be able to. This happens because of the pressure on assisted living facilities to fill their apartments up and bring in revenue. If you are not familiar with the laws in your state regarding assisted living and nursing home care you can go to your state's government website. The link to these laws for the state of Illinois can be found here.