diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/CentralServerData.java b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/CentralServerData.java
index 3293e61..2c8d7b1 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/CentralServerData.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/CentralServerData.java
@@ -1,10 +1,29 @@
 package ch.unibas.dmi.dbis.cs108.sebaschi;
 
+import ch.unibas.dmi.dbis.cs108.BudaLogConfig;
+import ch.unibas.dmi.dbis.cs108.gamelogic.Game;
+import ch.unibas.dmi.dbis.cs108.multiplayer.client.Client;
+import java.net.Socket;
+import java.util.Map;
+import java.util.Set;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 /**
  * This Class Represents an Object containing different Maps, Lists and Sets wherein a server object
  * can find all needed data. An instance of this object can also be passed to other class-objects uf
- * they need the same data.
+ * they need the same data. This Class is used to query for information in collections.
  */
 public class CentralServerData {
 
+  public static final Logger LOGGER = LogManager.getLogger();
+  public static final BudaLogConfig l = new BudaLogConfig(LOGGER);
+
+  private Set<Client> clientsOnServer;
+  private Set<Game> activeGames;
+  private Set<Game> gamesOpenToJoin;
+
+  private Map<Client, Socket> clientSocketMap;
+  private Map<Socket, Client> socketClientMap;
+  private Map<Game, Client> gameClientMap;
 }
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/GameSessionData.java b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/GameSessionData.java
index 621dbfe..fe2b850 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/GameSessionData.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/GameSessionData.java
@@ -1,5 +1,25 @@
 package ch.unibas.dmi.dbis.cs108.sebaschi;
 
+import ch.unibas.dmi.dbis.cs108.BudaLogConfig;
+import ch.unibas.dmi.dbis.cs108.gamelogic.klassenstruktur.Ghost;
+import ch.unibas.dmi.dbis.cs108.gamelogic.klassenstruktur.Passenger;
+import java.io.BufferedOutputStream;
+import java.util.Set;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Class that shall contain all non-game logik information relevant to a game session needed for
+ * client-server and client-client communication.
+ */
 public class GameSessionData {
 
+  public static final Logger LOGGER = LogManager.getLogger();
+  public static final BudaLogConfig l = new BudaLogConfig(LOGGER);
+
+  CentralServerData globalData;
+
+  Set<Passenger> passengers;
+  Set<BufferedOutputStream> clientOutputStreams;
+  Set<Ghost> ghosts;
 }
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/ServerLobby.java b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/ServerLobby.java
new file mode 100644
index 0000000..f0bbedf
--- /dev/null
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/ServerLobby.java
@@ -0,0 +1,10 @@
+package ch.unibas.dmi.dbis.cs108.sebaschi;
+
+/**
+ * This class is just everyone on the server, which games are open to join, who is in session. I.E.
+ * the context of the game just after joining the server, before starting a game and entering into a
+ * lobby.
+ */
+public class ServerLobby {
+
+}