Is an Intermediate-mass black hole a type of black hole?

A black hole is called that because when viewing it with the naked eye (visible light spectrum), the phenomenon appears to be a 2-D "hole" in space (or spacetime.) An actual Black Hole is much more...

When a huge star dies it's core becomes so dense it's own gravity starts to crush and collapse inwards the heart of a black hole is called the (Singularity)

Yes, blackholes do have mass. They take up space, however, it can be argued that it doesn't have mass because it technically doesn't have any weight.

A black hole gets more mass by sucking in more matter, i.e. a star or a cloud of dust. However, they do not have infinite density, because they are not infinitely small. Therefore the star that left...

A black does not have mass, because one matter enters it becomes a singularity.