I'm just starting as a Scrum Master, and I am looking for a good web based tool for a story board.  I am trying Agilefant, and they have something called leaf stories.I wonder what do they mean by that.I've read about User Stories, Technical Stories, Unplanned Items, but I can't seem to find a reference to Leaf Stories.  Can anyone clarify?
In Agilefant tool for Scrum, what are Leaf Stories?
scrum
Here is a bit of a description:The release, or project, view also  contains a story tree, which is a  sub-set of the product backlog,  consisting of the stories, which have  been assigned to the given release.  During other sessions, the PO and the  technical team continue to refine the  whats hot right now story. From  previous iterations in Agilefant, they  can see that the team can complete  around 15 story points per iteration.  Thus, the story is split to 10 child  stories, which are estimated to be  less than 10 story points each. These  10 stories are small enough to be  implemented in iterations, and dont  need to be split to finer pieces. In  Agilefant these stories are called  leaf stories. Leaf stories are stories  with no child stories. They are the  leaves of a tree, whereas their parent  stories are the branches.Please edit your question if that doesn't seem like a good answer.  I don't think it is a general Scrum term but rather something specific to the tool if you notice the 3rd last sentence from the quote.