Tumblr is a microblogging platform. If you think of different platforms on a timeline from the 140 character posts on twitter to the infinitely long blog entries on a provider like wordpress, Tumblr is somewhere in between.
Your blog may host longer posts, mostly made up of text and hyperlinks while your tumblr has quicker hits of content. Tumblrs are good for short form multimedia content. They're better at providing quotes, videos, pictures or links one at a time rather than commentary. Tumblrs are typically known for their short style, quick hits and ability to be reblogged and shared by other users on their Tumblrs.
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