Epoxy grout is made from two different resins mixed with a filler, making it very waterproof and bettered suited to harsher cleaning products. Epoxy thinsets offer greater bond strength and chemical resistance than cementitious grouts.
Although it has plenty of benefits, note that epoxy grout is more difficult to work with than regular grout. It also tends to look like plastic, which some homeowners don’t like.
Regular grout is very easy to shape in outside corners where tile wraps around a wall, curb or shower niche. It is harder to achieve the same effect with epoxy grout, since it takes a little longer to set up in the grout joint.