Last month, Gov. Steve Sisolak signed a “milestone” bill into law that will gradually raise the state’s Renewable Portfolio Standard to 50 percent by 2030.

It was a signing rejoiced by lawmakers — who approved the bill unanimously — and environmental groups, who have long touted the policy as a way to reduce the state’s reliance on carbon-heavy fossil fuels.

But lost in the conversation and publicity around the bill is a simple question — what exactly is a Renewable Portfolio Standard, and what does increasing it actually do?

Check out the video below for a rundown of how an RPS works, and how the bill signed by Sisolak will affect the state’s use of renewable energy: