Often used when someone helps another who can't manage by themselves due to absence, illness, or lack.

Assistance context

Conveys that the person has been entrusted to fulfill a role or duty for someone else.

Social commitment

Indicates that someone has given their authority or decision-making power to another person.

The person has the legal right to speak or make decisions for someone in judicial settings.

Carries a responsibility to act in the best interest of whom they represent, under legal obligations.

Usually pertains to specific issues or transactions, not every aspect of a person's life.