Definition: A "check-in" refers to location based post on a social network like Facebook or Foursquare. By "checking-in" through your mobile device or PC uses GPS-technology to find your current location. You can "check-in" from any location imaginable. Foursquare has created a rewards based program. After you "check-in" your friends will know where you are and specific badges will be presented to your profile i.e Mayorship Badge for most "check-ins" to a specific place. In addition, businesses will sometime offer incentives for specifically noted dates and times.