The exception is bitcoin ATMs — some do allow you to exchange bitcoin for cash, but not all. Installing a wallet directly on your computer gives you the security that you control your keys. Save my name, email, and website in this browser for the next time I comment. Do I need to add it as an option myself? The wallet address is then saved to the bitcoin blockchain. Valuable information and excellent information got here! When the two parties have done transacting, they close out the channel, and the resulting balance is registered on the blockchain.