The Mars Science Laboratory - Curiosity - is fitted with an array of sophisticated scientific instruments to analyze the environment on the planet, and see if it is now or ever was hospitable for life.
The American Chemical Society sponsored a nicely-done video explaining how Curiosity will go about poking and prodding (and zapping!) the landscape in Gale crater, its landing site:
The descriptions and video will really help you understand what the rover will do and just how complex this mission really is. We’re getting very, very good at this sort of thing, and Curiosity is the culmination of decades of exploration of Mars. It’ll land on the Red Planet at 05:31 (UTC) August 6 (01:31 Eastern US time), and I’ll be part of an online live video Hangout talking to experts about it as well. Come join us!