I believe it's the furnished basement of the house with its own entrance. There's a bedroom, sitting area, bathroom/shower, A/C, microwave, mini fridge, iron, TVs. It's nothing fancy but was suitable for my needs (a decent place to sleep and shower).
It's in walking distance of several stops along the North-Metro railroad, Target, the shopping mall, and Sarah Lawrence College. Convenient location to everything I needed since I didn't have a car.
The price was reasonable. I will likely stay there again.