Русско-англо-русский юридический словарь

"Title" means ownership. But ownership can be "encumbered," for example, by a tenant with a lease, which is an "interest," something which is less than full ownership but which is legally enforceable and usually recorded if it has to do with real estate. "Interests" include those established in probated wills and in trusts, those established in mortgages and judgment liens,and those established in recorded easements. (StackExchange)

Property rights are commonly identified as a right to own or possess something, such as land or abuilding, and to be able to dispose of it as one chooses. [...] Black's legal dictionary defines an interest as: "a right to have the advantage accruing from anything; any right in the nature of the property but less than title". Interest simply means having an ownership in property or having some kind of right to do something with or on the property. For example: having an easement on property, having a lease on the property, being a part owner, being the only owner, having a life estate etc. (What is Right, Title & Interest in Property? by Harshad Shah)