Instagram

Instagram is an online photo-sharing and social networking service that enables its users to take pictures, apply digital filters to them, and share them on a variety of social networking services, such as media sites including Facebook and Twitter. A distinctive feature is that it confines photos to a square shape, similar to Kodak Instamatic and Polaroid images, in contrast to the 16:9 aspect ratio typically used by mobile device cameras. (Available at: http://en.wikipedia.org/wiki/Instagram) 

(Image available at: http://www.flickr.com/photos/reallyniceimages/8022882705/)

Today there are more than 100 million monthly active users posting more than 40 million photos per day. (Available at: http://business.time.com/2013/04/09/a-year-later-instagram-hasnt-made-a-dime-was-it-worth-1-billion/) 

Instagram is used by ordinary people and celebrities alike. It is used to document important times, advertise events and products, plus the more stereotypical Instagram types, “selfies”, animal portraits and food images.