Curiosity's robot arm will drill into the Martian rocks and feed the powdered samples into its onboard chemistry laboratory.

WSJ: Mars Mission Seeks a Happy Landing

This is positioned on the same tool-turret as the drill, on the end of the robotic arm.

BBC: Curiosity Mars rover spins its rock drill

Just before halting its investigations, the nuclear-powered rover used the drill at the end of its 7-foot-long robotic arm to bore into a rock near where it landed and analyze the powder.

NPR: Mars Rover Curiosity Stands Down After New Problem