What is the difference between a deposit account and custodial regarding foreign financial accounts

Most standard bank accounts will be deposit accounts.  A custodial account is an arrangement to hold certain types of deposits (typically not cash). Source: SusanY1

A "custodial account" is an arrangement for holding a financial instrument, contract, or investment (including corporate stock, a note, bond, debenture or other evidence of indebtedness, a currency or commodity transaction, a credit default swap, a swap based upon a nonfinancial index, a notional principal contract (as defined in §1.446-3(c)), an insurance or annuity contract, and any option or other derivative instrument) for the benefit of another person. Reg. §1.1471-5(b)(3)(ii).

Source: KarenJ