There is an edit, a reply, and a quote button were we all know it is, but hardly anyone uses the 'edit' button.
Using it allows up to 48 hours later, you can fix a mistake, or add more information to your post.
Many peolpe make a post, then see they forgot something; and then make a new post right after it-
you can use the edit button to make fewer double posts

or to deleate your post you edit it too.