A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.
In astronomy, the term "compact star" (or "compact object") refers collectively to white dwarfs, neutron stars, and black holes.
In physics, exotic matter is matter that somehow deviates from normal matter and has "exotic" properties.
An exotic star is a hypothetical compact star composed of something other than electrons, protons, neutrons, or muons, and balanced against gravitational collapse by degeneracy pressure or other quantum properties.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
A preon star is a theoretical type of compact star made of preons, which are "point-like" particles conceived to be subcomponents of quarks and leptons.
In theoretical physics, Q-ball is a type of non-topological soliton.
A quark star is a hypothetical type of compact exotic star, where extremely high temperature and pressure has forced nuclear particles to form a continuous state of matter that consists primarily of free quarks, which can be modeled using the Calabi–Yau manifold.
A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a massive star.