What Constitutes as AoE?

I was just wondering what exactly qualifies for a spell to be AoE. Does it have to be a circle, or any shape? Do laser - type spells count as AoE? Here is a list of things that I would like to be explained as to why or why not these spells would be considered as Area of Effect: Graves Q Xerath Q Rumble Q Nidalee (Cougar Form) W and E Viktor E Maokai Q Vi (pre) Ult (Damage to things in her Ult path) Kennen Ult Braum Ult (Away from the epicenter)

Thank you in advance. Love yall!