What is the shortest thing that will be published because I have a story that is only close to 6000 words, I think it is worth publishing but is it long enough and if it is what is it called a novel or a novella or anything like that?

Please see the following site. It may be of use to you.

Good Short Novels: How Short is a Short Novel? (http://www.goodshortnovels.com/how.html)