Loan -- an asset on the Bank's balance sheet. It's a promise that Bob will repay the bank a certain amount of money, plus interest
Deposit -- a liability on the Bank's balance sheet. It's an account that Bob can draw from at any time, and the Bank will promise to honor or pay the deposit.
These are created at the same time, and balance one another. The bank does not need the Fed to create the deposit at all, the create it out of thin air when issuing the loan.
When Bob comes to withdraw from his account, the Bank will pay him from it's *reserves*. The banks reserves are a pool of assets, cash, and deposits from other customers that the bank holds in excess of it's loans.
The bank can get these from a lot of places, not necessarily the Fed -- they could offer checking accounts to other customers, and hold some fraction of the assets in a customer's checking account in reserve. Banks offer all sorts of incentives to get people to deposit long term(CD, Savings Accounts, e.g.) for this reason, but they almost never have 100% of the money they are loaning out held in reserves. Their entire bet is that only a fraction of the deposits will be withdrawn at any time.
The Fed doesn't need to be present for any of this, but they provide an important stabilizing function, ensure liquidity, and can adjust the money supply through open market operations or banking regulations.