IMEI (International Mobile Equipment Identity)
IMEI (International Mobile Equipment Identity) is a 15- or 17-digit code that uniquely identifies mobile phone sets. The IMEI code can enable a GSM (Global System for Mobile communication) or UMTS (Universal Mobile Telecommunications Service) network to prevent a misplaced or stolen phone from initiating calls. http://whatis.techtarget.com/definition/IMEI-International-Mobile-Equipment-Identity