Cellular phones have become one of society’s most ubiquitous accessories. What was once the domain of the wealthy technophile is now found in nearly every pocket or handbag from pre-teens to the elderly. For many, the cellular phone has even replaced the landline phone as their only telephone service. Yet with so many people purchasing cellular phones it is amazing that so few people know what they are really buying.
Although you may have purchased your phone from a service provider, in many ways the phone is not entirely yours. Many cellular phones are not able to be used at any place or with any carrier you choose. Instead, many cellular phones are locked by the manufacturer, and you can only use certain service providers with that particular phone. That holds true for all phones, unless you have purchased an unlocked cellular phone.
Inside your cellular phone is something called a Subscriber Identity Module, or as it is more commonly known, a SIM card. The SIM card is the key to your cellular phone, and all of your phones identifying characteristics and memory functions are stored there; you might call it the brains and DNA of your phone. The SIM card can be switched from one phone to another, and it allows you to instantly activate your new phone on the network while eliminating the need to reprogram information like your contact list on your new phone.
