Step 1 : Introduction to the question "5. Older phones, such as TDMA phones, did not come with a removable card which kept a subscriber's information (billing, number, etc.). However, newer phones, especially GSM phones, contained the small removable card which is called what?"
...1. NIN 2. PIN 3. SIM 4. TRW SIM stands for subscriber identity module. It keeps the information such as your phone number, your billing information and your address book. This makes it much easier to switch from phone to phone. Europeans used the system for years before Americans got this technology. (My exchange student came over here with a phone and her father told her to just take out the SIM card so she could purchase another card to use the phone here in the US. We looked all over and went to a couple cell phone stores before figuring out that we just didn't have that type of technology at the time - and that was in 2000!)
