A lease extension is simply the continuation of an existing Lease Agreement, usually on a month-to-month basis. A lease renewal is essentially a new lease, and is usually for the same term as the previous lease. For the landlord, the benefits of renewing a lease include the stability of knowing there's a commitment for the term of the new lease, the savings of not having to find and move in a new tenant, and the ability to raise the rent for the new lease.