Leases and Rental Agreement should be written agreements so that there is a clear and listed understanding among landlord and tenant which is easily enforceable.  A verbal agreement, while seemingly easy and informal, often leads to disputes as either side may forget key agreements as time passes.  As such, states will not enforce oral agreements after one year.  A rental agreement is generally known as a month-to-month rental in which the agreement is automatically renewed at the end of each set term.  A lease on the other hand, is a rental for a set period of time, usually 6 months to a year, as long as the tenant pays the rent.  When a lease expires, it does not renew itself automatically.