From Texas to New York, natural gas has radically changed the energy landscape in America. But how did the practice commonly known as fracking explode so suddenly, and where is it actually happening? In the two-minute video above, Alexis Madrigal, The Atlantic's senior technology editor, explains the two main technological innovations that have tapped formerly unreachable gas in shale. Animated by Lindsey Testolin, this clip is part of a six-part video series in The User's Guide to Energy special report. For a look beyond the basics to the larger conversation about the pros and cons of natural gas, see Kyle Thetford's piece on the boom.