Personal journal or just a place to vent?

So this is my first post, I'm kinda excited but I'm also wondering for what will I use this for? I've always been under the impression that no one would read my blogs, in that case it would be my own personal journal that the world can see or do I will I just post here to vent anger and frustration from everyday life? I can see myself posting the most profane obscenities just after a 4 hour shift at work. Maybe both but that really depends on who reads my posts. Well, only time will tell I suppose ...