What does that mean for you?
Availability depends on the people or services involved, the place you live and the rules they apply. A displayed balance does not guarantee a buyer, a fixed exchange rate or immediate access to a bank transfer.
Fees, a spread and withdrawal restrictions can affect what you receive. Selling can also have tax implications, so keep records and use current official guidance.
Can you picture an example?
Imagine a screen quotes a dollar value for your bitcoin. That quote is not the same as dollars already sitting in your bank account. An actual exchange and any money withdrawal are separate actions.
What should you remember?
Understand who is handling the exchange and what its terms allow. This page describes the idea without instructions to trade, a suggested service or a promised cash amount.