Question

what is dark matter ?

Answer 1

Dark matter is a type of matter that doesn't react with any of the forces we know like gravity, light etc.
It isn't clear by now that it's just a myth or a mind boggling fact.
For more info head on to this article - https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

Answer 2

Cosmological observation explain  us that composition of universe is as follows 
68% dark energy , 27 % dark matter , 5 normal matter 

Dark Matter :
Dark matter is a invisible matter  not made of the baryonic particles which we can detect by passing radiations .  it is made of wimps and axions  .

Note : it is not a anti matter .
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