Shard

Definition

A shard is a term that describes a way to deal with lots of players in an MMO Game. To Deal with thousands of players, most games use multiple servers (those are the shards) where players move out to adventures and interaction. Due to the nature of this, a player on one shard cannot interact with players from an other shard.

EVE Online

EVE Online uses two shards. Players are located on one of two servers so cannot interact with each other. The two servers are Tranquility for most of the world and Serenity for China.