Social networks are social structures composed of groups connected by relationships. Facebook began as a platform for college students and later expanded. Tuenti is a Spanish social network for those over 14 to create profiles, add friends, and share messages, photos and videos. Twitter started as an internal project in 2006 and launched publicly that October, originally called twttr. A blog is a regularly updated website that collects chronological articles from one or more authors. Myspace is a social network owned by Specific Media and Justin Timberlake, launched in 2003. Yahoo was founded in 1994 and incorporated in 1995, headquartered in California.