If you report a post, it means you believe that it violates the forum rules, and you are not happy to see it.
Therefore, as soon as you report it, it disappears from your screen, so it no longer bothers you.
When the moderators receive your report, they look into the matter. Then there are two possible outcomes:
If the rule vialation is confirmed by ANY single moderator, actions will be taken -- Mostly it gets deleted. Therefore you will never see it again.
If none of the moderators sees any violation with the post in question, it will stay there. However, since you are not happy with that post, it doesn't show up in your screen so it doesn't bother you any more anyway.