An orc is a fictional humanoid creature that is part of a fantasy race akin to goblins.
The exact definition of the orc varies greatly depending on the setting. Orcs typical to western fantasy tend to strongly resemble humans, but are much taller and more muscular, have green or tan-colored skin, and have tusks. Orcs typical to Japanese-style fantasy tend to possess pig-like features such as snouts and pig ears, or are sometimes little more than gigantic, bipedal pigs.
Other varieties exist, and anything that is called an orc in-fiction can be tagged as such.