Instagram is a social media platform launched in 2010 that allows users to share photos and 60-second videos. It was acquired by Facebook in 2012 for $1 billion. The app originally only allowed square images but was updated in 2015 to support different image sizes and longer videos. It has over 500 million active users and is most popular among 18-24 year olds. Users can share content publicly or privately and view content from others. The platform also generates revenue through sponsored posts targeted towards specific demographics.