How it works

Cryptourrencies are currency (a medium traded for value) that is held only digitally. Unlike a physical dollar bill, they live in networks that take account of transfers made to and from your account (your account is generally a “wallet” of some sort - something that is tied to your digital identifier and just scans the network’s code for transactions related to you, then adds or removes coins from your account accordingly).

Transfers are made through bank network transactions, individual transactions, or transfer to physical asset (eg, goods or services). Most US dollars are actually held digitally, but because they can be transferred to physical asset (dollars, which you get at an ATM, etc), they aren’t technically cryptocurrency - no fiat currency is.

Cryptocurrency is not physical. The same currency can’t be in two places at once - once you spend it, it is gone. You can’t respend it, because you don’t possess it. But digital assets are different - it’s possible to spend the same money from the same account twice.