Tumblr’s feature for sharing another user’s post is called a reblog.
When a user reblogs a post, it appears on that user’s own Tumblr blog while retaining a connection to the original creator. Reblogging became one of Tumblr’s defining features because it allowed images, text, GIFs, links, and videos to travel rapidly through networks of followers.
A reblog can also include a user’s own commentary, creating a visible chain of reactions and additions. This differs from simply copying and pasting content because Tumblr preserves attribution and displays the post’s history as it moves between blogs.
Reblog is sometimes confused with “retweet,” Twitter’s sharing mechanism. The functions are similar, but Tumblr’s reblog culture developed its own conventions, including commentary chains, fandom circulation, image-based humor, and extensive remixing. Reblogs, likes, and replies are commonly counted together as a post’s notes.