Depending on the jurisdiction, if a landlord terminates a tenancy, the landlord may be required to give the tenant a notice, commonly called a notice to quit or notice to vacate prior to instituting formal legal proceedings. This is true whether the termination is "for cause" (i.e., because the tenant has violated part of the rental agreement) or without cause (i.e., because the landlord has simply decided to terminate the tenancy).
If the termination is for cause, the tenant may have a short amount of time (perhaps from 3 to 10 days, or longer if the rental agreement provides a longer period) in which to correct the violation. Common causes for eviction include nonpayment of rent or a breach of the lease (such as keeping a pet when pets are not allowed). In some cases, depending on the laws of the particular jurisdiction, a landlord may post an unconditional quit notice, meaning the tenant can do nothing to correct the violation.
In some jurisdictions a landlord may terminate tenancy without cause if the tenancy is not for a specific length of time (such as a month-to-month tenancy), or if the lease has expired, and the tenant has not moved. In many jurisidictions, written notice of termination must be given (generally 1 to 3 months) before the landlord commences an eviction.