A GSM cell phone uses the Global System for Mobile Communications (originally Groupe Spécial Mobile). Most cell phones use either the GSM or CDMA systems; CDMA stands for Code Division Multiple Access.
GSM is the cell phone system used in most parts of the world. A GSM cell phone is a good option for those who travel often or who regularly update or change their cell phone because the GSM cell phone operates using a SIM card which can be changed or moved into another phone with ease. Additionally, GSM cell phones usually have better signal strength when compared with CDMA cell phones.