I just got a comment on my blog that is linked as a pingback.....it is like a short hyphenated comment
It is is method of posting a comment. You can enable or disable it for each post. The option is on the right menu when you are creating a post. I am pretty sure you can turn it off for future posts but you will need to manually update all the older posts. Now If I may be cynical for a second, disable it on all your posts. This is nothing more than a SPAM delivery vehicle. Once they find you allow pingbacks they will flood you with their SPAM.
i am not sure i really understand, i see my blog posts on their site. Would it only appear if I accept the comment?
Their post will only appear on your site if you approve it. I have never had one I even considered approving so I don't know how it will affect your post being on their site.