A mortgage loan is another name for a mortgage: a loan made by a lender to a borrower for the purpose of financing real property, secured by that same property as collateral. The two terms are used interchangeably in everyday speech and in much of the banking industry, with "mortgage loan" sometimes preferred in formal lending documents to make clear that the discussion concerns the loan product itself rather than the legal lien that secures it.
Whichever term is used, the underlying arrangement is the same: the lender advances funds to the borrower to purchase or refinance property, the borrower agrees to repay the loan over an agreed term with interest, and the lender holds a legal claim against the property that allows it to force a sale through foreclosure if the borrower fails to repay.
For how mortgage loans are structured, priced and repaid, see the main Mortgage entry.