[claude]

In spite of the efforts of many to help understand the world of "prepaidgsm" and other providers, there are many of us who are still faced with a lot of questions.
After several days surfing the net, I discovered how insufficient the information are.
1- SIM cards: there are different types but nobody tells you which one goes into your phone and, if you are like me, you don't know what you device can take.
2- I have still not understood the time management of those cards, buying more time has several options and if I grasp the literature, if you call to buy there is a charge but if you go to a retailer it is free???
3- If all the time is not used while abroad, is the credit still available on a future trip?
There are still other questions that are not very clearly answered or not at all.
Every site is making great efforts to help consumers but the whole thing is getting pretty confusing for non experts like me.
Simplicity would be welcomed and surely as profitable.