In a commercial lease that's month to month for one year....?

Isn't it true that even though the duration of the month-to-month lease is for one year, the landlord may evict or you may vacate the premises prior to the expiration of the year? Or is the month-to-month for one year a term for years, thus making it a lease for one year, under which the landlord may not evict prior to the expiration of the one year?