'Corned' describes meat, most often beef, that has been cured in a salt brine, historically using coarse crystals or 'corns' of salt, which is where the term comes from. It refers to the curing method itself rather than a specific dish; corned pork and corned mutton exist alongside the more familiar corned beef.
The meat is submerged in a brine of salt, curing salts such as sodium nitrite, and often spices like peppercorns, bay leaf, and garlic, for several days to weeks. This firms the texture, turns it pink, and gives it a distinctly salty flavor. Corning was originally a preservation method used before refrigeration, and today it is used mainly for flavor and texture rather than necessity.