I understand that through calculations well beyond my comprehension, that something like 90% of matter in the universe is unaccounted for. I also understand that this is referred to as Dark Matter.
There is some speculation that this Dark Matter could be locked into White Dwarfs, black holes, Neutron stars, brown dwarfs etc.
So here is my question. Is Dark Matter Actually a specific type of matter or is it a catch all name for unaccounted for matter? Is it tangible or is it just a question mark place holder for the unknown?
For example, suppose a black hole was discovered that was say 20% more dense then originally calculated. Would locating that extra 20% subtract from the amount of dark matter we speculate is out there?