Reblogging

Reblogging (or, in Twitter parlance, retweeting) is the mechanism in blogging which allows users to repost the content of another user's post with an indication that the source is another user.

It was first developed by Jonah Peretti at Eyebeam Art and Technology Center's R&D program under the project 'Reblog' (from where the term originates) as an open-source tool for individually-run blogs. Tumblr then built it into their social network for re-sharing posts within the network, and similar features ("Retweet" on Twitter, "Share" on Facebook) then followed.