There are three main types of matter in space: baryonic matter, dark energy, and dark matter. These make up different parts of the matter in the universe, but are dramatically different in their makeup and quantity. Here's a breakdown of what makes each type of matter, and what their place is in space.
Baryonic Matter
Baryonic matter is a type of dark matter that includes any matter made of baryons. This means that anything composed of protons, neutrons, and electrons is classed as baryonic matter. While this includes things like elements, chemicals, and most physical matter, baryonic matter actually only makes up a tiny proportion of the matter in the universe. Baryonic matter is less than 5% of the matter in the observable universe, with the rest being comprised of dark matter and dark energy (which we'll cover next).
Interestingly, black holes are considered to be baryonic matter. While black holes are completely different from other baryonic objects such as planets and stars, they are also classed as baryonic matter due to them being made out of incredibly dense neutrons.
Dark Energy
Dark energy is another form of matter found in space and accounts for around 70% of the matter in the universe. There's a lot we don't understand about dark energy, but we do know about several of its qualities. Dark energy isn't very dense, resulting in it not interacting with any forces other than gravity. Dark energy acts in opposition to gravity, and as a result, matter is repulsed by it. It also has an extremely large negative pressure, meaning that it pushes everything away from itself.
Because of this negative pressure and opposition to gravity, dark energy is the force behind the universe's expansion. In fact, dark energy has such a strong influence that the expansion of the universe is constantly increasing in speed, despite the incredible size of space it is enlarging.
Dark Matter
Dark matter makes up the remaining 25% of matter. Dark matter comprises particles that we can't observe. These particles don't absorb, emit, or reflect light, and as a result, can't be seen. They also don't emit any electromagnetic radiation, which makes dark matter difficult to detect at all. Most of our understanding and observation of dark matter comes from seeing it interact with other objects that we can see; in essence, we can't see what dark matter is, but we can see how it behaves by watching other, visible matter.
It's important to note that while dark matter doesn't emit any light, it does have mass – in fact, dark matter makes up for five times the mass of baryonic matter (aka the matter that we can observe and interact with). Because of this, it interacts with other forms of matter through gravity. As a result, dark matter is responsible for holding galaxies together, keeping them stable, and preventing them from flying apart.