Generally, refers to the duty of a life tenent to maintain property in a reasonable state of repair. There is an exception for ordinary wear and tear. If the individual personally occupies the land, this duty is limited to the extent of the reasonable rental value of the property. Otherwise, it is to the extent of income that is derived from the property.
There is a similar duty for a tenant for a term of years. It is not, in this case, limited to the extent of income or reasonable rental value. The duty of the tenant for the term of years is usually governed by state statute as a lessee. Residential lessee's generally are not under a duty to repair according to such statutes.