The quest panel interface contains a tabbed icon list of the quests in each act, and a brief description of the status of the current quest.
Click on a quest icon to select it.
Gold embossed quest icons are active quests your character has not yet completed.
Hollow, dark grey icons represent quests you have not discovered yet.
You can open the quest panel via hotkeys, or via the Mini Panel. The default hotkey for the quest panel is Q.
Quest Text Button
This is the button embossed with the exclamation point inside a text bubble. It appears in the lower right hand corner of the quest panel.
Left click on this button to play back the text and voice of the quest message for the selected quest.