Flickr (stylized as flickr ) is an image hosting and video hosting website, and online community that was created by Ludicorp in 2004 and acquired by Yahoo! in 2005. In addition to being a popular website for users to share and embed personal photographs, the service is widely used by bloggers to host images that they embed in blogs and social media. Yahoo reported in June 2011 that Flickr had a total of 51 million registered members and 80 million unique visitors.  In August 2011 the site reported that it was hosting more than 6 billion images and this number continues to grow steadily according to reporting sources.  Photos and videos can be accessed from Flickr without the need to register an account but an account must be made in order to upload content onto the website.
1. Photos (some of which are geo-tagged with EXIF data)
2. Tags for photos
Users tag the photos they upload,
Users are encouraged to tag and license their photos, and a variety of beautiful presentation schemes are provided
Flickr was one of the first sites to integrate Creative Commons licensing into their site, allowing people to license their photos (if they wanted) for use under a variety of different CC-based schemes.