Chock the wheels, what's that involve?

Yesterday, I took her out for 20 min spin. Been above 0 for several dys, and past couple of them had a bit of heavy rain, so looked like the right time. Started to flurry up a bit today.

 

http://www.amazon.com/b?ie=UTF8&node=15708131

Its just little things that go behind the wheels to insure your car does not roll away since there will be no e-brake on and it will be in neutral.