In KonoSuba's first episode, Aqua is said to have extremely high stats on all stats but below average intelligence and worst luck. Then, she was told that she can be anything but Arch Wizard since it requires intelligence. Arch Wizard, being a Wizard, and as we can see from Megumin, is a class that uses magic to attack. Aqua's low intelligence prevents her from becoming a Arch Wizard, means that magic is related to intelligence.
When they checked Megumin's adventurer card, both Kazuma and Aqua mentioned that Megumin, being from the Crimson Demon clan, has a very high intelligence and is an Arch Wizard. It was also shown that Megumin can cast advanced spell, Explosion although only once a day due to her limited mana.
However, during the fight with Dullahan, Aqua cast Sacred Create Water on a level where it destroyed the gate of the city, causing damage on the level of Megumin's Explosion if not higher.
My question is, since Aqua can't be Arch Wizard due to her low intelligence, while she shows that she can do magic on the level that of Megumin, then what does the intelligence stats do in KonoSuba world? While at it, what are the other stats in KonoSuba and what do they do?