A tenant at will is a tenant who has the landlord's permision to stay on the property past the expiration of the rental agreement. Also, a tenant who occupies rental property with the landlord's consent and makes rent payments without a written lease is called a tenant-at-will. A holdover differs from a tenant at will in that the latter has permission of the landlord to stay beyond the expiration date of the agreement, while the holdover tenant does not. A tenant at will is typically required to continue rent payments as long as they are permitted to remain.
State laws, which vary by state, govern tenancies at will, and generally, the state's landlord-tenant law, including eviction laws and security deposits laws, still applies. For example, if the tenant-at-will fails to pay rent, the landlord may demand possession and immediately file a dispossessory warrant seeking possession in court. Local laws should be consulted for specific requirements in your area.