We've used it very frequently, as have other family members. You can choose when searching whether you want a room in someone's house or a place to yourself - we always choose a place to ourselves, usually an apartment. It's basically a way of booking self catering accommodation. Advantages are that you can arrive and leave any day and stay for as long or short as you want (usually min 2 nights). Not really worth it for very short stays as the cleaning fee is the same whatever the length.
We prefer self catering when travelling as OH likes to shop in local markets and cook, but eat out some of the time too. If staying for a week or longer, having a washing machine is handy- the website lists all the facilities.
In response to OP - food is not provided though sometimes a few basic items are there.
If you want to travel self catering, we've found AirBnb the best site, but always read reviews carefully.