I'm aware this question is a year old - apologies for not replying at the time.
But, for anyone who runs across this question and has the same question, please visit
http://docs.adobe.com/docs/en/aem/6-1/author/communities/blog.html
Short summary :
For AEM 6.0 and earlier :
Blog feature was based on a page template for author-only editing.
Journal feature allowed community content to be entered from publish environment (UGC).
As of AEM 6.1
The Blog author-only template has been deprecated.
Journal is being re-purposed as the Blog feature.
- JK