[dragonwriter]

> Because we found no better analogy, we named them "holes" despite the fact that they are basically the opposite: an object with enormous mass.

Strictly speaking, the defining character is enormous density, not mass. And the black hole is arguably a name for an effect of the object, not the object itself; the object itself is (or is in the process of becoming; verb tenses get weird when time gets weird) infinitesimally small, but the “black hole” generally refers to the space bounded by the event horizon.

[Santosh83]

A black hole can literally be considered severely warped spacetime. The high gravity is a consequence of the severe warping, and as for the internal contents, they don't matter to external observers and physics (so far) has very little to say about it.