This is a stub.
This is another example of TANSTAAFL. Bandwidth is "bits per second". It is the amount of data your computer can handle, or your Internet Service Provider allows you, or the amount the website you are accessing can support. It is paid for, but not directly. You pay for it in a lump sum. So, the individual transfers are not paid for. This makes websites, and advertisers on those websites, treat it like it is "free". This has unintended consequences.
More to come.