I have a Samsung prepaid trac fone which has a SIM card in it.
What are they for and in what ways do you use one in this scenario?
I know zero about these cards except that it stands for subscriber information something.
go to this link
A Subscriber Identity Module (SIM) card is a portable memory chip used mostly in cell phones that operate on the Global System for Mobile Communications (GSM) network. These cards hold the personal information of the account holder, including his or her phone number, address book, text messages, and other data. When a user wants to change phones, he or she can usually easily remove the card from one handset and insert it into another. SIM cards are convenient and popular with many users, and are a key part of developing cell phone technology.
1. Sim cards allow the user to use multiple phones with just one account.(Of course you will only be able to use one phone at a time).
2. Sim cards also allow the user to store contact information on the chip itself. Most phones are defaulted to store the information to the phone only. You must go into your settings (contacts for Nokia users) and copy the information to the Sim card.
This comes in very handy if your phone decides one day to stop working.
3. You can download your contact information to your computer by simply purchasing a Sim card reader (.generally only $10-$15).
*Note - Sim card readers will not allow you to download ringtones, wallpaper or any other accessories to your phone.
How SIM Cards Work
Subscriber Identity Module
Ithere are some SIM card which are country specific, it can operate only in that country that it has originated.
The SIM holds billing information & user ID you can calls easily using someone else's phone by merely installing your SIM that is unique in that mobile phone.
some phones are locked with sim so you cant exchange them and you need first to unlock then to switch provider.
A SIM is essentially a holder for two types of data, the identity of the phone (the information which allows a phone number a connection to a network to be established), and some contact information. The space for contacts was useful in earlier generations of phones but smart phones today have far too much contact information (but in terms of how many contacts, and what information is stored about each) for the SIM to hold it all, so most people save the contact info into the phone's own memory.
You can read a full explaination here:
SIM cards have the information needed for using the phone on a particular phone service. Unless the phone is unlocked (Tracphones are not unlocked), then no other SIM card can be used and is not interchangeable. The card gives information to the company of which phone including IMEI number (basically like a serial number specific to each phone) so it can be allowed on the network for use. The SIM card also allows you to store telephone contact information (name and phone number) of your different contacts. The phone will not allow phone calls (except to 911 emergency) without the SIM card. More information can be found here: http://www.wisegeek.com/what-is-a-sim-card.htm Note: prepaid phones from services like Tracphone will not allow the use of SIM cards to be used in another phone, even if it is from the same company. The only way to use another Tracphone SIM card in a different Tracphone device is to activate the SIM card to that phone, but will disable it from use with other phones and disable the card that you had with your phone from being used with your phone. In short, only one SIM card is able to be used at a time per Tracphone.