Sometimes there is not a difference between the two and then sometimes there is a massive difference it just depends on the situation. One very clear difference is Bloggers are online dependant throughout their writing or research, Journalists may work online but the majority of their work is done through tv or radio and even newspapers. Also a Blogger tends to find information to write about that sometimes may not have been heard of and can make it into mainstream news. As well as bloggers tend to stick to one niche ( area) of blogging By either Posting about blogging tips, technology, world news e.t.c.
Journalists will sometimes report unreliable and false news too. Journalists are mainly experts with expert training and will extract information about specialised stories and subjects through their sources and interviews. With being a JOurnalist they have to go round finding facts go through all their information before reporting it, Bloggers all they have to do is set up a website or more post a couple of interesting stories, information or help and advice from time to time , include links multimedia content and a way for readers to drop comments or share the post via social media sites such as FACEBOOK, TWITTER and GOOGLE+ . Journalists do from time to time blog about certain information to go into an article online , adopt a more informal approach to news reports rathe than what it is like on the television , as well as adding information to a story thats online linking or commenting to other stories based on other news material found online.
So as some Journalists may be Bloggers, certainly Bloggers aren't Journalists. In my view there is a massive difference between the two. Being a Journalist is more of a Job being paid A fixed salary and with blogging i think its more of a hobby and can be fun, even though some bloggers , blogging websites do have full time paid workers running them.