I see blogging as writing your thoughts/ideas in the length of an essay or could be in the form of online journals or diaries as a way of sharing information or ideas.
Micro-blogging is different from blogging as micro-blogging is a combination of instant messaging as well as blogging. This is normally in the form of short messages which are posted on the profile. For example, Twitter is a micro-blogging site, as it allows short messages to be delivered to individuals mobile phones and it provides a quick and easy way to communicate with people.
Tumblr is a difficult one, as it can be seen as a blogging platform, but also as a micro-blogging platform as you can post it for blogs. I use Tumblr to blog for the Communication Activism and Social Change Unit, however, since moving to WordPress I have used it to Micro-blog, so I guess it’s both. I find Tumblr unique in the way that it gives the individual an option to either micro-blog or blog.