How are black holes different from neutron stars?
They are both remains of the supernova BUT
The fate of the core depends on the starting mass of the star.
A star that began 6 to 30 times as massive as the sun will end up as a neutron star after a supernova. A neutron star is about as massive as the sun but it is often less than 16 kilometers in diameter. Such star is extremely dense. It weighs up to 100 million tons. Neutron stars spin very rapidly.
Suppose a star begins with a mass 30 times or more the mass of the sun. The star will undergo a supernova. But this supermassive star will not form a neutron star. The core left behind after the supernova of a super massive star is unbelievably dense. It is so dense, in fact, that it is actually swallowed up by its own gravity. The gravity is so great that nothing, not even passing light, can escape it. A black hole is the remains of a super massive star after a supernova. Black holes have been described as 'cosmic vacuum cleaners' because they swallow any nearby matter or energy.