Gold: Has some actual usage value, but is mostly of value because people/nations are willing to accept that it has value. When it comes down to it, for whatever reason, the central banks put their faith in gold (aka, a shiny rock).
Silver: Like gold, but for the little people.
Fiat (e.g. the US dollar): Has value because government(s) say it does. Governments have the most guns.
Crypto: No real value. Backed by absolutely nothing. Some people think it will replace other "money", as it is not controlled by bankers and governments -- people will trust it as money because other people trust it as money. Some people just want to buy some now and sell to the bigger fool.
I'd love to see a system independent of the banksters and politistitutes. I don't understand why the movers and the shakers have decided that a shiny rock with marginal useful value should represent true wealth. But at the end of the day/decade, where should I store my wealth?
