What material(s) define " hard court " in tennis these days?

Question

What material(s) define " hard court " in tennis these days?

Answer 1

Hard courts are usually made from concrete or asphalt. Examples:

The U.S. Open is played on DecoTurf, an acrylic hard court.

The Australian Open is played on a synthetic hardcourt Plexicushion.

Answer 2

concret i think

Answer 3

I think the smooth cement kinds you see in the U.S. open and the courts around your area.  Well at least the ones in Portage they're hard.