what's the game french people play where they throw a ball to the ground to hit other balls

It’s pétanque — the French boules game where players toss metal balls as close as possible to a small target ball, and can also try to knock other balls away. It’s especially associated with southern France and Provence.

How it works

• A small target ball, called the cochonnet or jack , is thrown out first.
• Players then throw their boules from inside a circle, keeping both feet on the ground.
• The goal is to finish with your boule closest to the target, or to hit opponents’ boules out of the way.

Common name

People may also call it jeu de boules or just boules , but the specific game you’re describing is usually pétanque.

TL;DR: Pétanque.