so unlimited should be replaced with "how ever much you can get with the bandwidth restrictions". It takes me longer to understand. My bandwidth is restricted.
Correct. Your bandwidth/transfer are always restricted in some form or another. As I said, unmetered bandwidth is definitely possible, but there are still limits involved.
is data transfer different the bandwidth?
Yes, they are different, but the majority of hosts simply use them interchangeably. They normally refer to bandwidth when they really mean transfer, or data transfer.