Ooh a guinea pig! I had to zoom in pretty close to see what this furry sausage actually was. So cute, looks like he or she is a spoilt and happy little fellow

Most smaller shops use some well-known third party to handle the payments, and you can tell as you are redirected to their site when it’s time to enter your card details. Some even use Amazon Pay if that’s the only one you trust.

well, fiat money is issued by a central authority and its value depends entirely on the faith people have in that central authority. Compare that to monetary systems based on the gold standard, where a unit of currency has a fixed value in terms of gold. When the dollar followed the gold standard, it was technically possible to exchange dollars at the bank for a fixed amount of gold. While with fiat, you could say that the market decides how much gold one dollar is worth.

Bitcoin and other cryptocurrencies are more like gold or silver than they are dollars or euros or whatever other fiat currency. The value that gold itself has is determined by a lot of things, but ultimately it comes from its rarity. You can if you want go out into the hills and spend time and energy digging up gold. Likewise, you can if you want spend time and energy mining bitcoin. This is why people often say bitcoin is digital gold - it’s rare and it takes time and energy to find.