Phantom is a browser plugin and non-custodial wallet that may be used to handle digital assets and communicate with digital apps and smart contracts. Being non-custodial entails that you retain ownership of a small number of confidential pieces of information rather than having your assets kept in a single location. You are responsible for keeping the contents in your Phantom wallet secure, just as you would need to protect your actual wallet or purse from pickpockets when you are out and about. This is different from holding your country's cash in a bank account. Phantom Wallet