# What does the ATC instruction "Make left traffic, runway 19L" mean?

I'm playing Prepar3D and when coming in for a landing I'm usually told something like Make left traffic, runway 19L. I'm not sure how to interpret this because I'm not a pilot.
Should I go to the left of 19L for my downwind leg so the runway is to my right, or should I go to the right, with the runway on my left?
Also with parallel runways should I go to the left of 19L exactly or is it the left of 1R? I'm very confused!