Optimus is a technology which saves battery life by changing the graphics driver: http://www.nvidia.com/object/optimus_technology.html
Most of the new laptops come with this new technology...
Nvidia didn't provide support to Linux, so the community developed its own one: http://bumblebee-project.org/
There would be a way to install it in any Linux distro, but installing it from source is a nightmare (I've already tried). So, for some distros it is easier to install, as you can see from the Bumblebee project.
I would like to know of Mageia 3 will have a Bumblebee package on its repositories.