Diablo II: Lord of Destruction/Jewels and Runes
The expansion offers two new item types to socket into weapons and armor: jewels and runes. Jewels feature various magical properties and can be placed inside a socketed item much like a gem.
Let's take a look at runes, which are identified by a particular syllable--for instance, you may discover the Ral rune or the Tal rune. The runes can be placed into sockets to instill items with new magical properties. However, runes are best used in their "runeword" form.
For instance, in Act V you receive the Ral, Ort, and Tal runes for completing a quest. If you place the runes inside a socketed shield in the correct order, you receive a much better bonus than if you place the runes in an incorrect order. For more on Diablo II: Lord of Destruction runes, visit GameSpot's Diablo II: Lord of Destruction hint and FAQ section at: http://gamespot.com/gamespot/filters/products/0,11114,370600,00.html