When Facebook launched in 2004, it was a fairly static collection of profile pages. Facebook users could put lists of favorite media on their "walls" and use the "poke" button to give each other social-media nudges. To see what other people were posting, you had to intentionally visit their pages. There were no automatic notifications, no feeds to alert you to new information.
In 2006, Facebook introduced the News Feed, an individualized homepage for each user that showed friends' posts in chronological order. The change seemed small at the time, but it turned out to be the start of a revolution. Instead of making an active choice to check in on other people's pages, users got a running list of updates.
