A tenant who enters upon premises by reason of a contract with the landlord is a contractual tenant. Such a tenant holds an estate which is subject to the terms and conditions of the grant. Once that tenancy comes to an end by effluxion of time or otherwise and the tenant holds over without the will or agreement of the landlord, he becomes a tenant-at-sufferance. This is strictly a common law concept. But sometimes there is a statute which gives security of tenure to such a tenant after his contractual tenancy has expired. Where such a statute exists he now holds the premises no longer as a contractual tenant because there no longer exists a contract between him and the landlord. But he nonetheless retains possession by virtue of the provisions of the statute and is entitled to all the benefits and is subject to all the terms and conditions of the original tenancy.
– Nnaemeka-Agu, JSC. Petroleum v. Owodunni (1991)