the difference is inheritance is a general word and the inheritance means one who derives the interest in property, But Succession is that who is the next successor of the predecessor or the person who dies. i.e C dies and A is the successor and A dies B is the successor. When C dies both A and B are the inheritors but B is not successsor.
Hence Inheritance is deriving interest by blood reation or genetic connection. But Succession/intestate succession is only after a person dies.
Successor is successor of predecessor but inheritance is all the person after successor as well as successor. In other words Inheritance can be successor as well as next to the successor.
Inheritance cannot be claimed till the kartha( the person who acquires property) but can be claimed by succession i.e. after kartha dies.
Inheritance can be by succession but succession cannot be by inheritance. Instestate Succession is after death of a person. Inheritance may be after or before death of person.
Go through illstration
A is a father and B is a son. B gets propery after A dies. it is intestate succession.
C is Grand Father, A is his son ( father of B) and B is A’s son/daughter ( grand son/grand daughter of C).
then C (grand father) died, B (grand son) gets property from C (grand father), then B (grand son)too has share in the C (grand father )property as per Hindu Succession Act 1956. then the property B (grand son) gets from C (grand father) is inheritance but not succession. Succession as well as inheritance is by A (father) because he derive property from one's parents or ancestors and intestate as per hindu succession act is who dies without making any testamentary ( documents/deeds for example WILL, gift deed, partition deed )) . But the share of property which A (father) got cannot be partitioned until he dies intestate ( without making any testamentary document). Further after the death of A(father) only, B (son of A) gets right in self acqired property of A. otherwise it is property by succession as well as inheritance. One cannot ask the inheritance in self acquired property but one B( as a sonof A) can ask the property inherited to his predecessor A (father) as a successor of the person who died intersate C(grand father). So inheritance right is more powerful than succession. succession comes into effect only after death. But inheritance has limitation i.e. he can ask the property after the share of successor. But in succession, he enjoys all of the property. if there are 3 sons in succession, then 3 sons are successor and has equal shares i.e. Succession by inheritance as well as intestate. Succession will not come to grandson i.e. B, but he has inheritance.