Prestation / Nagotiorum gestio / Solutio indebti / Quasi - Delict

PRESTATION - Subject Matter of the obligation or the Conduct required to be observed by the debtor (giving, doing, or not doing) 

NAGOTIORUM GESTIO - this refers to managing the properties of another person, and that act of managing the property of another person is without the consent of the owner of the property. And if by that act of managing the property, he was able to save the property, therefore the owner of the property, has the obligation to pay damages.

(Example: is usually when the house is on-fire and you have save it even if you are not called or you have help and save a properties of other people, that is tantamount to negotiorum gestio). So if something happens to them, then the owner of the property that was saved has the obligation to pay for damages. And that is an obligation arising from QUASI-CONTRACT. 

SOLUTIO INDEBTI - it is based on the principle of unjust enrichment. It is that no one shall enrich himself unjustly at the expense of another. (benefited on the expense of another)  

QUASI - DELICT - when they arise from damage caused to another through an act or omission, there being fault or negligence, but no contractual relation exists between the parties