Frac or FRAC is a term that can refer to several things, including a method for extracting oil and natural gas known as hydraulic fracturing or fracking. Fracking is a well stimulation technique that involves the fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure injection of "fracking fluid" into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine will flow more freely. Fracking involves blasting fluid deep below the earth’s surface to crack sedimentary rock formations, including shale, sandstone, limestone, and carbonite, to unlock natural gas and crude oil reserves. Different chemicals are added to the fracking fluid for different purposes, based on the rock type and other specifics of a fracking site. Sand is the fracking industry’s favored proppant, with high-purity quartz—known as “frac sand”—prized the most for its round shape, uniform size, and crush resistance.

In summary, Frac or FRAC can refer to hydraulic fracturing, a method for extracting oil and natural gas from deep in the planet.