Bitumen is a tar-like substance. It is one of the things we get from crude oil in an oil refinery. It is made from the residue left in in the still.
A lot of bitumen is also found buried in sand in Canada. It is too thick and sticky to flow through pipelines. It has to be mined by digging or by heating it with steam. This melt it while it is still underground.
Bitumen is used for road surfacing and for roofing. It has to be heated to melt it. It is made from the residue left at the bottom of the still.