Have you ever lived in an apartment, it's usually a self-contained housing unit but it only occupies a part of a larger building.
I have always lived in a house. I am not familiar with living in an apartment.
They usually call these apartment buildings or even a complex.  In Britian they are called a block of flats.  It's not always the greatest to live in them, but economical
I guess it would be cheaper than renting or owning a home then.
Well, there are several kinds. For instance in cities like New York, people actually own them and then in other areas they are rented by tenants.  So it just depends on where you are if it's cheaper or not.
Oh so people can own them also.
Yes, in some areas the apartments are owned.  Now those owners may lease them out as well, and so then they would be rented.  In our area, you just rent apartments and yes it would be a cheaper option.
I see. It can really vary wherever you are it seems.