legal ground
Article 402 of the Civil Code
Where the property specified in Items 1 to 3 of the first paragraph of Article 395 of this Law or the building under construction specified in Item 5 is mortgaged, the mortgage registration shall be handled. The mortgage is established at the time of registration.
Article 394
In order to ensure the performance of the debt, if the debtor or a third party mortgages the property to the creditor without transferring the possession of the property, if the debtor fails to perform the due debt or realize the mortgage according to the agreement of the parties, the creditor has the right to be compensated in priority for the property.
The debtor or the third party specified in the preceding paragraph is the mortgagor, the creditor is the mortgagee, and the property that provides guarantee is the mortgaged property.