Gonna admit, I never understood this game. All I can understand is they furiously scrub the floor while the ball(?) slide on the floor.
It's stone (because they are actually made of stone). And the basic rule is quite simple - for every stone you have closer to the target center than the closest opponent's stone you get a point. The rest is tactic about blocking and scoring you learn over time from watching.
In regards to Curling, I'm damn impressed on the rapid brushing to ensure maximum slide to knock out the enemy stones tho... although I can't get the shouting and yelling.