Quest

Quests are objectives given to the player to complete. Quests have an Experience reward, and often modify your karma. In Fallout, Fallout 2 and Fallout 3 there are usually many different ways to solve quests. The Fallout Tactics equivalents, called missions, and Fallout: Brotherhood of Steel quests are much more linear.

Quest types
There are three different types of quests:
 * Main quests form the main storyline of a game.
 * Optional or side quests, are quests which are entirely up to the player to complete or not and do not prevent achieving the goals of the main storyline, though it may tie in to the story, often significantly.
 * Unmarked or freeform quests are small things to do on the side and do not even appear in your quest log (which in the Fallout games is usually a Pip-Boy variant).These are usually just simple tasks or fetch quests.

Quètes

Zadanie In Fallout: New Vegas, a large number of the Quests are named after famous song titles, like:

That Lucky Old Sun by Beasley Smith,

Eddy My Love(E-DE My Love) by Aaron Collins,

Come Fly With Me by Jimmy Van Heusen and Sammy Cahn

Cold, Cold Heart by Hank Williams

Can You Find it in Your Heart by Tony Bennet

My Kind of Town by Jimmy Van Heusen and Sammy Cahn

Ain't That a Kick in the Head by Jimmy Van Heusen and Sammy Cahn

High Times by The Grateful Dead