Shale gas is a type of natural gas that is found trapped within shale formations, which are fine-grained sedimentary rocks. It is primarily composed of methane and is extracted through a process called hydraulic fracturing, or fracking. This method involves injecting water, sand, and chemicals into the ground to create fractures in the rock, allowing the gas to flow more freely. The discovery and extraction of shale gas have significantly impacted the energy industry, particularly in countries like the United States. It has contributed to a shift towards cleaner energy sources, as natural gas burns more cleanly than coal, reducing greenhouse gas emissions.