"The Sims 2: Happy Holiday Stuff (The Sims 2: Festive Holiday Stuff in Europe) is an official "stuff pack" that re-packages the content from The Sims 2: Holiday Party Pack with twenty new additional items. It is considered the third "stuff pack" and is available for sale from major video game outlets (unlike Holiday Party Pack, which was only available for purchase via Electronic Arts's online store in the US and as a retail version in the Asia Pacific region). Happy Holiday Stuff adds additional holiday themed content to the game, and was released on November 7, 2006.
A revised edition of The Sims 2: Holiday Edition was released simultaneously with Happy Holiday Stuff; containing the original The Sims 2 game and the Happy Holiday Stuff expansion in one bundle, similar to that of The Sims 2: Holiday Edition released in 2005.
On October 24, 2006, EA announced a special mini version of this pack titled The Sims 2: Happy Holiday Mini Pack. The mini pack was targeted specially at owners of the previous releases of Holiday Edition and Holiday Party Pack and includes the twenty new items not included in those releases.
The Happy Holiday Stuff pack is the first and only Sims 2 game or expansion that does not use a key to unlock the installation. It includes 63 items including 18 new items from The Sims 2: Happy Holiday Mini Pack."
Source: Wikipedia, "The_Sims_2_Stuff_packs," available under the CC-BY-SA License.