How does dark matter and dark energy affect the universe and other matter around it?

Under the theory of dark matter every possible answer humans have thought are just theories because Dark matter and energy are believed to be needed in the galaxy in order for the galaxy to make sense. By this I mean that due to the power of gravity galaxies should not be able to be formed and each planet or star should just be floating randomly in space. Although little is known about dark matter many believe it is true and believe that all of the know matter in the universe we know only consists of 5 % of matter, Dark matter consists of 25 % and dark energy consists of 70 %. Dark matter is an invisible substance and dark energy us a force that repels gravity. This is a very modern research that many countries are taking a part to solve the mystery of what dark matter is and to find a way to prove that it exists. With the universe creation many scientist believe that the universes expansion should in fact be slowing but it is actually increasing in the rate of expansion.

sources:

https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

http://go.galegroup.com/ps/headerQuickSearch.do?quickSearchTerm=dark+matter&inputFieldNames%5B0%5D=OQE&searchType=BasicSearchForm&userGroupName=43riss&nwf=y&prodId=SCIC&stw.option=&ebook=&quicksearchIndex=OQE&spellCheck=true&hasCoProduct=false