An initial payment:
• when buying it gives the seller some confidence you will complete the purchase and pay the rest.
Example: Sam just paid a deposit of $2,000 on a new car, and needs to borrow $18,000 to finish the deal.
• when renting it is held until the end to pay for any damages etc.
Example: Alex lost the $400 deposit when the washing machine flooded the apartment.
But in banking it is any money paid into an account.
Example: Carol made a $500 deposit into her bank account, and now has a total of $3,000 on deposit.