What is a poker room skin?

A "skin" is a poker room with someone else's software, but original graphical elements. For example, Eurobet is a skin of PokerRoom.com. That means the software provider is the same, but the design of Eurobet and PokerRoom are slightly different, especially the table view.

Also they do separate tournaments, promotions, etc.

Some skins have the same tournaments and players from all the skins are allowed to play.

The group of skins creates a poker network. Sometimes players have only one login and username to all of the network rooms. For example, Prima poker: you can play in Royal Vegas Poker, 32Red Poker, or Bet365 Poker with the same username.

The biggest Poker Networks which offer a poker room skin are iPoker (Noble Poker, Titan Poker), Prima Poker (Royal Vegas, 7 Sultans, Poker Time, etc.), On Game (PokerRoom.com, EuroPoker, Eurobet, Hollywood Poker etc), 24h Poker and others.