What is dark matter? According to the Standard Cosmological Model, ΛCDM makes up about 26.8% of the mass of the universe. He spends his sleep over the scientist's eyes. They call it the Holy Grail of Physics and even Science. They look for it everywhere: in the entire cosmos, on Earth, and even underground. They spend billions of dollars a year to find it. Thousands of scholars around the world are looking for it. Americans, Russians, Chinese, Japanese, Europeans and even Poles are looking for it. The Large Hadron Collider at CERN and other accelerators around the world are looking for it. So far, not a single dark matter particle has been found. Thousands of publications have been written about dark matter. Despite the enormous costs incurred and continued, all efforts made to find dark matter particles were unsuccessful. The title of the book is "DARK MATTER? SUPER MASSIVE BLACK HOLES? MOND? and the curves of the rotation of galaxies" What is the relationship of dark matter with supermassive black holes and MOND? Well, that all of these concepts have a common lineage, namely the rotation curves of spiral galaxies. So let's ask ourselves the following questions: WHAT CAN DARK MATTER BE? 1. some unknown form of matter - WIMPs? (Weakly Interacting Massive Particles), Can the term dark matter mean: 2. Fictional matter, a mathematical trick, something like epicycles, equants and deferents in Ptolemy's geocentric theory to explain the retrograde motion of Mars and other outer planets of the solar system? Or maybe the dark matter problem is due to: 3. wrong assumption of the type of galaxy rotation curves? 4. wrong method of calculating the mass of galaxies? 5. Isaac Newton's erroneous law of universal gravitation ˗ MOND theories? (Modified Newtonian Dynamics, Modified Newtonian Dynamics) 6. Or maybe dark matter and dark energy do not exist? As suggested by Adam Riees, "So what is this essential thing? Do we have any tips? It depends who we ask about it. Adam Riees, a man whose radical, pathosic rhetoric ushered in the era of dark energy, suggests something food for thought. What if we don't know everything about how gravity works? Maybe dark matter and dark energy don't exist? Perhaps for the past four centuries we have been blind to the slight inaccuracies of Newton's law of attraction, which are perhaps the key to reclaiming the lost universe. "