Add-on

Add-ons or expansions (also called expansion packs) are content created for games that are released separately from the main game release.

Fallout 3
The first game in the Fallout series to feature downloadable content was Fallout 3, with a total of five add-ons released.

Fallout: New Vegas
Fallout: New Vegas has a total of four pre-order bonuses and six add-on packs. The pre-order bonuses were later condensed into the Courier's Stash add-on.

Fallout 4
Fallout 4 features seven add-ons, of which two include new settlement objects, and one being a graphical upgrade.

Fallout 76
Instead of add-ons, Fallout 76 uses updates in regular intervals to provide new content.