check and deposit, what do they mean?

[newlife]

I read an article about wire transfer scams and saw a paragraph about an example of scam:

"You offer an item for sale on the Internet or newspaper. Someone says they will buy but will have to pay for it with a check made out for more than the sale price. The buyer wants you to deposit the check and wire the difference. The scam? The check you receive is fake and your bank may come after you for the total amount of the phony check. You're out both the amount of the fake check and the amount you send by wire, plus a bundle of bounced check fees."

I don't know what to ask. I just don't understand, especially the term like check and deposit. I find the definition of these words and apply to the context but it doesn't make sense. Could you explain the scam for me?

[Anglika]

A check/cheque is a written document authorising your bank to transfer a sum of money from your account to a named person, either as a deposit or as cash.

A deposit is a transfer of money made from your account into another person's account.

The illegality in this passage is that the "purchaser" sends more money than is actually required, then asks for the difference to be returned to them, but in fact has never made any real transfer of moneys as there are none. At no time has he any intention of in fact making a purchase. He is cheating you of the money you are being asked to "return".