They both use 4 community cards and 1 holecard as a kicker...
88 33 6
Vs.
88 33 A
They both have 2 pairs but the A5 guy has the better kicker...
Be aware of things like this when the board pairs. Beginners often overlook these situations.
Think of you flopping Q J 3 with QJ
You now have top 2 pair. Even someone with Aa or KK is beaten right now.
Now the turn brings a 3 for Q J 3 3
Now KK or AA beats you because Kings and 3s are the better 2 pair....