Here are some scientific pictures to help you understand what Dark Matter is:
In the middle u can see galaxy which is Matter, what you see around is Dark Matter. Scientists have been observing Dark Matter through the Hubble Telescope, which they used to think was empty space turned out they found it had a function and it's properties resembled that of Matter however reacts differently.
Ratio of the universe: Matter, Dark Matter and Dark energy
Now what is Dark Energy? no one knows, After the Area of Dark Matter, the energy that resides outside of it the dense dark abyss, no one knows what it is made of or what it is yet. thus they just called it Dark Energy, the reason they know that Dark Matter is different because they know that it is a different form of matter.
So yes Matter and Dark Matter are pairs because they both are made of Neutrons and both are a FORM of matter. However we do not know what Dark energy is yet.
