Quest variations

Most standard quest tasks take one of the following forms with a variety of quest objectives:

Gather a number of items and return them to the quest giver or some other NPC.
Kill a number of creatures and return to the quest giver or another NPC.
Deliver an item (usually a letter or a package) or some items from the quest giver to another NPC.
Kill a number of creatures, loot a single quest item or several quest items from them, and return with the quest item(s) to the quest giver or another NPC.
Use a profession to acquire or make a single or several items and return with the item(s) to the quest giver or another NPC.
Escort an NPC from one place to another, usually through a dangerous area.
Many quests that involve escorting an NPC through an area full of mobs can be quite difficult to do alone. "The Defias Traitor" quest in Westfall is one such example, as is the Forsaken quest in Silverpine Forest "Escorting Erland." The NPCs of those quests are suicidal hotshots who engage each enemy within a 10-yard radius despite your directive to keep them alive, leaving you to save them from themselves as well as all the other mobs attempting to eat both of you. In addition, many escort quests have scripted events where a number of enemies will spawn right in front of you, forcing you to fight them at once. Failing these quests occurs commonly, but you can easily abandon it and start over. Or, in some cases, if you find yourself overwhelmed during quests like these, abandon the quest and run away as far as you can, and try it again when you are at a higher level or have some backup coming with you. "The Defias Traitor" is notorious as a favored target for Horde attacks, which simply extends the duration of the quest (and, in some cases, necessitates a complete restart of the quest).
Some players find Escort quests extremely annoying due to the fact that the NPC almost always walks, regardless of the reason for the escort (even when you are escorting an NPC during an escape, they only run if they are moving to attack something).
When soloing escort quests, a useful tactic is to stay slightly ahead of the NPC, so that you can tank with any enemies that attempt to ambush your escort. This tactic is much more effective if the escort quest is at a much lower level than your character.
Find and speak to an NPC, which usually leads to a subsequent quest. When such quests are designed to have the sole purpose of leading a player from one zone to another, they are known as Bread Crumb Quests[1]
Build and/or maintain a level of reputation with a specific faction.
Find a container item, loot an item in it that gives you a follow-up quest.
Explore a particular region or area and return to the quest giver or some other NPC.
NOTE: Some quests have a time limit, which is counted down in a clock that appears under the mini-map.