There are no "stupid questions...." actually, this is a good one....
There are many terms in real estate that are confusing....there can be several different terms that actually define the same type of subject property. With this said, "apartment" is a term generally associated with rental units while condo may imply ownership. On the other hand, condos can be rented as well.
If you are buying, you should probably focus your attention on listings that are shown as condos, villas, or townhomes.