Bitcoin is a digital currency. It doesn’t exist in the sort of physical form the currency & coin we’re used to exist in. It doesn’t even exist in an application as physical as Monopoly money. It’s electrons – not molecules.
But consider just how much cash you personally handle. You obtain a paycheck that you take to the financial institution – or it’s autodeposited without you even seeing the paper that it’s not printed on. After this you make use of a bank card (or a checkbook, if you’re old school) to get into those funds. At best, you see 10% of it in a money form in your pocket or in your pocketbook. So, as it happens that 90% of the funds that you manage are virtual – electrons in a spreadsheet or database.