A more thorough explanation:

Definition: Action in rem is a legal action that deals with a specific property or thing rather than a person. It is a legal proceeding that seeks to establish the rights of a person over a particular property.

Examples:

• An action in rem can be taken to determine the ownership of a piece of land.
• A maritime lien is an example of an action in rem, where a ship is arrested to secure payment of a debt.

These examples illustrate how an action in rem is used to establish the rights of a person over a specific property or thing. In the first example, the action in rem is taken to determine who has the legal right to own a piece of land. In the second example, the action in rem is used to secure payment of a debt by arresting the ship.