Question: What kind of texture do I have on my walls and/or ceiling? Can I patch it? What's the best way to repaint or match the texture?
Answer 1 ('knockdown' texture):
One common type of wall texture is called "knockdown texture", a.k.a. "knockdown drywall texture", a.k.a. "Mediterranean texture" or Mediterranean-type drywall texture*.
A knockdown finish (knockdown texture) uses drywall joint compound ('sheetrock joint-compound'*)
which is sprayed in dollops over the surface of the wall, allowed to set briefly,
and then lightly troweled to “knock down” the tops of the dollops. The result is a rough, uneven finished surface, which is sometimes called 'earthy', 'warm', or 'rustic'; the texture can provide a more natural feel because it looks similar to old stucco. It is sometimes called "Mediterranean texture" because it looks like southern-European (or Spanish-style) stucco