For their Diablo I: Hellfire and Diablo II: Lord of Destruction counterparts, see Runes.
The Runes return in Diablo III in the form of skill enhancements. Unlike their second generation counterparts, Diablo III's Runes are not used in socketed items but are used in conjunction with skills to give many additional effects that may aid the player suit his/her playing style. They function in a manner very similar to Glyphs in World of Warcraft.