Cutscene
A cutscene is an animated cinematic sequence that plays during certain moments, that the player cannot control. Most often, it involves only NPCs, however it can sometimes include the player performing an action to show correlation.
A cut scene can be a reward for completing a quest in numerous instances, such as 
[15-30] The Kor'kron Vanguard! which rewards players with the Battle of Angrathar the Wrathgate cutscene.
Tour
A tour is a cut scene where:
- you lose control of your character for a time
- your point of view is moved around the world.
- (often) some form of narration occurs while the tour continues.
An example of a tour happens during (
[15-30] Survey the Land). At the completion of the tour, control of your character is returned to you. Often, completing the tour satisfies a quest objective.
Variations
Not all tours take complete control of your character away for the duration.
In some cases (such as the 'halaa bombing runs' in Nagrand, or the quest [25-30] The Drakkensryd, you have autonomy to use items in inventory during a tour. In the latter, you can even conduct combat.
In other cases (such as 
[80 Daily] Static Shock Troops: the Bombardment), you are in an actual vehicle, and are limited to the options presented by that vehicle while the vehicle moves around the world.
Common cutscene placements
- At the creation of a character, giving lore and backstory of the race the player is about to play.
- Upon the defeat of a dungeon or raid boss.
- When nearing the conclusion of a zone storyline.