When a ship is taken on rent, it is known as ship chartering. Just as people take an apartment or a car for rent, some people may rent a ship based on their requirements. It could be to transport passengers or cargo.
Renting a ship is known as ship chartering and it begins with the shipowner and a second party entering into an agreement. In shipping parlance, this agreement is known as a charter party.
The party that rents out the ship are the shipowner and the second party who is taking the ship...
https://www.marineinsight.com/maritime-law/ship-chartering-process-the-ultimate-guide/