What meaning for lease line?

Leased Line refers to a type of telephone circuit. It is not used much anymore. This is a continuous telephone line between two locations. It is always on, you do not dial a number as with a normal phone line. Leased Lines are used to monitor fire and burglar alarms and for low-speed data transfer. There is a monthly fee paid to the phone company to use Leased Lines. Many phone companies will no longer install new LL services, but will continue to honor existing leases.