Adds several new aspects to Settlers of Catan but the two major ones are creating knights to protect the land from invading barbarians and building city improvements that confer benefits upon that city's owner. Adds tactical complexity to the game and game length.

The expansion is about fishermen.

The Great River of Catan is an expansion for The Settlers of Catan. The expansion consists of a tile with 3 hexes and a river.

Now up to six players can muster their knights against the scourge threatening Catan! 2007 edition

Now five to six players can sail into the uncharted and explore and settle the mysterious islands near Catan!  this is the 2007 edition!

This is an expansion for The Settlers of Catan. Players can build shipping lanes, which are very similar to roads.  this is the 2007 edition !

Settlers of Catan Travel Edition is, as the name says, a Travel Edition of The Settlers of Catan.
The rules of the game are the same, but there are some changes between the two editions:

Allows you to add up to two more opponents to The Settlers of Catan. this is the 2007 edition!