What is the difference between a lease and a rental agreement?

A lease commits both parties to a fixed term, typically twelve months, during which the rent and terms are locked and neither side can unilaterally change them. That stability is the tenant's main protection: the landlord cannot raise rent mid-term or end the tenancy without cause. In exchange, the tenant is on the hook for the full term, and breaking it early usually means owing rent until the unit is re-rented, plus whatever the lease and state law allow in fees.

A rental agreement, usually month to month, renews automatically each period until either side gives notice, commonly 30 days, though many states require more, especially for longer tenancies. It buys flexibility for people who may move, at the cost of stability: the landlord can raise the rent or change terms with proper notice, and can end the tenancy without needing cause in many places. State and local law heavily modifies both, notice periods, rent control, and just-cause eviction rules vary enormously, so the governing document is your state's landlord-tenant statute as much as the paper you signed. Read the actual terms on subletting, pets, repairs, and deposit return, and get every agreement in writing regardless of type.