The Gold Edition contains the main game and also the three available DLC’s.
So the games within this compilation are:

* Assassin’s Creed: Revelations
* Assassin’s Creed: Revelations – The Ancestors Character Pack
* Assassin’s Creed: Revelations – Mediterranean Traveler Map Pack
* Assassin’s Creed: Revelations – The Lost Archive

This special edition was also released as two other packages: as a physical
package with the name Ottoman Edition and as the Ultimate Edition through
the PlayStation digital storefront.

Differences are mainly the platforms. The Gold Edition is only available on
Windows, and the digital Ultimate Edition (not to be confused with the
physical Ultimate Edition) only on PlayStation 3. The physical Ottoman
Edition is available on disc, and on Xbox 360 and the PlayStation 3.

Assassin’s Creed Revelations Gold Edition