A rental lease is a contract between a landlord and a tenant that outlines the terms of the tenant's occupancy. The lease should include the names of the landlord and tenant, the address of the rental property, the length of the lease, the rent amount and due date, and any other terms and conditions of the tenancy.
Rental leases are important because they protect both the tenant and the landlord. The lease outlines the terms of the agreement between the two parties and spells out the responsibilities of each party. This document helps to avoid misunderstandings and disagreements down the road. If a property manager is used, the property manager typically fulfills the responsibilities of a lease on the landlord side. Violations in the lease, from the tenant, can be grounds for termination.
The Nophin Blog lists important information about what's commonly found in a lease.