I am not expert on Iranian law and in particular I am not an expert on a Habs (حبس), so I can only provide a limited answer.
A common law legal life estate is transferrable creating a life estate per autre vie. A legal life estate holder can also lease the property (although the tenant's lease ends early if the legal life estate holder dies before the lease ends). In that respect, it is more flexible.
Sometimes an equitable life estate interest in a trust isn't transferrable, however, which is closer to a Habs (حبس).
A legal life estate, unlike an equitable life estate interest in a trust, doesn't require a trustee.
A trustee who holds real property in which the beneficiary has an equitable life estate can sell or transfer the real property and apply the proceeds to a substitute property or to distributing investment income from the proceeds (without the beneficiary's consent), unless the trust agreement expressly provides otherwise, which isn't possible in a legal life estate. In a legal life estate, the remainder interest owner(s) and the life estate owner(s) must agree to sell a 100% fee simple interest in the property subject to the life estate to a third-party.
It is legally permissible to lend money secured by a life estate, or by a remainder interest, but as a practical matter, this is almost never done except in related party transactions designed for their estate tax reducing effect. In contrast, a trustee can borrow money secured by the property in the trust including real property in which there is a beneficial life interest, unless the trust expressly provides otherwise.
Historically, a legal life estate was the default estate in land created when A conveyed to B without adding "heirs and assigns" language following the name of the grantee. Many jurisdictions have changed the historical common law rule, however, as it is a trap for the unwary.
A legal life estate is created by operation of law in a primary residence of a surviving spouse in some state inheritance laws, but this varies considerably from one U.S. state to another.
At the death of a life estate owner, the property passes by operation of law to the remainder interest owner, although it is customary to record a death certificate or affidavit of death or both, to make it clear in the public record that the life estate owner has passed. In a trust with a beneficiary with an equitable life estate, the trustee would convey the property from the trust to the remainder interest owners if they are entitled to the property outright under the trust.
Often, the trustee would sell the property when the life estate beneficiary dies and distribute the proceeds to the remainder beneficiaries of the trust (often children from a first marriage, when the life estate beneficiary is a spouse from a later marriage).
A legal life estate is a real property interest. I've seen some sources that describe a Habs (حبس) as a contract, although it isn't clear if that is being used in a precise legal category sense.
