Green tick mark below my answer

Question

What does the best answer causes, like I've posted some answers, and they have marked it as correct. What does it actually do? Like increase my xp or anything else?

Answer 1

increases ur xp by 20-30 approx ☺

Answer 2

Best answer mark give 10xp exactly plus 1xp per upvote ^^

Answer 3

Ok many thanks @gaurav

Answer 4

++ fame ++