A SIM card or Subscriber Identity Module is a portable memory chip used in some models of cellular telephones. The SIM card makes it easy to switch to a new phone by simply sliding the SIM out of the old phone and into the new one. The SIM holds personal identity information, cell phone number, phone book, text messages and other data. It can be thought of as a mini hard disk that automatically activates the phone into which it is inserted.
A SIM card can come in very handy. For example, let's say your phone runs out of battery power at a friend's house. Assuming you both have SIM-based phones, you can remove the SIM card from your phone and slide it into your friend's phone to make your call. Your carrier processes the call as if it were made from your phone, so it won't count against your friend's minutes.
If you upgrade your phone there's no hassle involved. The SIM card is all you need. Just slide it into the new phone and you're good to go. You can even keep multiple phones for different purposes. An inexpensive phone in the glove compartment, for example, for emergency use, one phone for work and another for home. Just slide your SIM card into whatever phone you wish to use.
Dual Sim Card
Triband phones are meant to work in more than one country, but the countries that the phone can receive service in depend on which three frequency bands are included on the phone. Dual SIM cards can give a cell phone user an additional phone number with which to work.
A card from another provider will not work in such a phone unless it is unlocked by the wireless provider. Not all phones can accept dual SIM cards, but there are adapters available to turn almost any late model phone into a dual SIM phone.
A SIM card can come in very handy. For example, let's say your phone runs out of battery power at a friend's house. Assuming you both have SIM-based phones, you can remove the SIM card from your phone and slide it into your friend's phone to make your call. Your carrier processes the call as if it were made from your phone, so it won't count against your friend's minutes.
If you upgrade your phone there's no hassle involved. The SIM card is all you need. Just slide it into the new phone and you're good to go. You can even keep multiple phones for different purposes. An inexpensive phone in the glove compartment, for example, for emergency use, one phone for work and another for home. Just slide your SIM card into whatever phone you wish to use.
Dual Sim Card
Triband phones are meant to work in more than one country, but the countries that the phone can receive service in depend on which three frequency bands are included on the phone. Dual SIM cards can give a cell phone user an additional phone number with which to work.
A card from another provider will not work in such a phone unless it is unlocked by the wireless provider. Not all phones can accept dual SIM cards, but there are adapters available to turn almost any late model phone into a dual SIM phone.