“Oil Shale” refers to the kerogen-bearing rock; “Shale Oil” is the petroleum-like liquid produced from the oil shale.

How is shale oil produced?
Oil shale is processed through high-temperature heating into shale oil, an oil similar to petroleum. The processing can take place either above ground in retorts once the oil shale has been extracted (ex-situ process) or it can be done more slowly while the oil shale is still underground (in-situ process). In-situ processing allows for fewer waste products, lesser land impact and a smaller amount of water are required for the process.

What is oil shale?
Oil shale is a sedimentary rock which contains kerogen; it can be converted via pyrolysis into a synthetic crude oil; distilled through high-temperature heating into oil similar to petroleum; or burned directly as a low-grade fuel.

this was taken from the website of American Shale Oil llc