Right in Rem:
A right in rem is available against the world at large; it is a right available against persons generally. Examples are rights of possession and ownership.
Right in Personam:
A right in rem is available only against a determinate person or persons, corresponds to a duty imposed on determinate individuals. Examples are the right to receive compensation for false imprisonment or defamation; or the right to recover a debt from the person who owes me the money. Rights under a contract are rights in personam for only the parties thereto are bound.
Thus, my right lo the peaceably occupation of my farm is right in rem, while my right to receive rent from tenant is right in personam. My right lo liberty and reputation is right in rem, while my right to receive compensation for false imprisonment or defamation is right in personam.
The distinction between the two lies in the number of persons subject to the duly respecting my right a right in rem avails against the whole world while that in personam binds only a particular person or persons.
Rights in Rem are Negative:
Rights in rem are almost always negative. It is a right to be left alone. It is a right that people should not interfere with my ownership. Rights in personam are usually positive. It is acquired because the subject stands in some special relationship towards another person as in the case of a contract.
Rights in personam may also be negative as in the case of sale of goodwill when the seller undertakes not to set up a rival business within the prescribed area and period of time.
Rights in rem are said, though incorrectly, to be rights in expect of things, because the persons of incidence being indefinite, there is greater emphasis on the thing or object of the right.
Right in personam is spoken of as personal rights because persons bound being determinate, personal relation are stressed. In fact, both classes of rights imply the person of incidence as well as object.
It is for this reason that rights in rem are known as real rights while rights in personam as personal rights.
An important kind of jus in personam in jus ad rem. A jus ad rem is a right to have some other right transferred. I have just ad rem when I have a right that some other right shall be transferred to me or otherwise vested in me.
Here one right is the subject-matter of another right. It may be illustrated by axon tract to assign property. The right itself is necessarily in personam though the right to be transferred may be cither in rem or in personam.
(i) the right of A after signing the contract for the purchase of land is a right in personom against B that B shall execute a deed of sale in his favour and transfer the property.
After the execution of the sale deed the right of A is a right in rem available against the whole world that nobody shall interfere with his ownership.
(ii) Is right is right in personam being available .against the common carrier only and if by the negligent or willful act of the carrier the goods are destroyed C has his remedy to recover damages against the carrier alone.