Bitumen of Judea is a sticky and black substance that comes from natural sources like tar pits or oil shale. It's been around for a really long time and was used in ancient times for many different things, like waterproofing boats and houses.
Think of it like a really thick and gooey syrup that can be spread on surfaces to make them waterproof. But, it was also used for healing wounds and as a medicine.
Sometimes it was mixed with other stuff like wax or resin to make it thicker or more malleable. People have been using bitumen of Judea for thousands of years because it's so versatile and useful.