A more thorough explanation:

Definition: Negotiorum gestio is a legal term that refers to the management of another person's affairs by an actor (negotiorum gestor) in that person's absence, without authority but out of concern or friendship.

For example, if a person is out of town and their neighbor notices that their lawn is overgrown, the neighbor may decide to mow the lawn without being asked to do so. This is an example of negotiorum gestio.

However, the actor is bound to conduct the matter to a conclusion and to deliver the transaction's proceeds to the person, who likewise must reimburse the actor for any expenses incurred. A negotiorum gestio does not exist if the gestor acted self-interestedly or if the owner expressly forbade the gestor from acting on the owner's behalf.

It is important to note that the negotiorum gestor acquires no right of property by means of the interference, and they are strictly bound not only to good faith but to ordinary care and diligence. In some cases, they are held responsible for the slightest neglect.

Overall, negotiorum gestio is a quasi-contractual situation that can arise out of concern or friendship, but it is important to act in good faith and with care when managing another person's affairs.