Posting for me takes a longer time to write with much revising and editing.
Posting makes me seriously consider what I write about and how I present the information.
Posting is for show, and I'm not a showy person as a rule.
Posting is for celebration/revelation.
Journaling comes more quickly without much revision and little editing.
Journaling bares more of my soul without too much self examination.
Journaling could be any subject I choose for that day without worrying about the outcome.
Journaling is private, and that's who I am and always will be.