In most cases, the shipowner chartered (leases) his ship to a charterer (lessee of the ship).
The charterer pays the shipowner money for the use of the ship. This money is paid either for a certain time (time charter) or for a certain voyage (voyage charter).
With time charter the shipowner receives a rate per day, with voyage charter a price rate per tonne of cargo.
Another option is bareboat charter. Here the ship owner leaves his unmanned ship to the charterer for a certain period of time.