D&D 5E Advantage: +5 to a roll, roll twice, or both?

[Herobizkit]

This is in response to the thread titled Halfling rogue sniping from the second rank.

Regarding Hiding and Passive Perception (BR60), when a creature attempts to detect a hidden opponent and that creature also has Advantage, they get a +5 to the roll.

As I understand Advantage, a creature gets to roll its check/attack twice and take the higher score.

Does this +5 also include, or replace, the current Advantage rules for rolling twice, or is it used only in the case of passive perception rolls?

 

[Agamon]

If you roll, you roll 2 d20s, take the best one. If it's a passive score, you get +5 to the passive score. You never get both the extra die and the +5.