Metaphysics is, essentially, believing in immutable properties. Things will always be the same, and they are not connected between each other. Everything is in its own little box.

When people say “communism doesn’t work because people will always be selfish”, they are being idealist. But they are also being metaphysical.

You can also experience metaphysical materialism, which we still see today in science of all things. A biologist doesn’t ask what chemical compounds blood is made of. They ask how does it interact with the rest of the body, what kind of cells are in blood? But never what their chemical makeup is, and how physics interact with biological entities, or how human bodies evolved the way they did by studying our Australopithecus ancestors. That is not their job, their job is to be metaphysical and say that human bodies have always been the way they are (because they don’t study prior to homo sapiens), and how human bodies behave biologically.

Dialectical materialism is two components that, if I can be approximate, were “fused” together. It’s not entirely true bc it’s not as simple as taking dialectics and putting it with materialism, it obeys its own rules and such. But there are the two component parts.

Hegel for example, who formalised dialectics, was an idealist. To him, dialectics happened through the will of God (or in other words, through some mystical process that took shape in our ideas).

Metaphysics is the contradiction to dialectics and idealism is the contradiction to materialism.

Best reference on this topic is Fundamental principles of philosophy https://en.prolewiki.org/wiki/Library:Fundamental_principles_of_philosophy

the word “metaphysics” comes from the Greek meta, which can be interpreted as meaning beyond, and from physics, the science of nature. The object of metaphysics (especially in Aristotle) ​​is the study of the being which is found beyond nature. While nature is movement, the being beyond nature (supernatural being) is immutable, eternal.