Coral reefs are important to have in your aquarium if you are going to have any coral fish. Coral fish rely on them for their own survival. While coral reefs do not directly benefit from coral fish, they can use them indirectly for their survival. Coral reefs can include live coral, in addition to dead coral, which more or less looks like rock. Many coral reefs have several different corals and multiple species of coral fish that all live together going about and doing their own things.
Coral fish will be harder to maintain, and they are more territorial than coral reefs, so you have to make sure that you are selecting your aquarium additions wisely. Coral fish often get along fine in an aquarium so long as other coral fish do not pose a threat to them. Corals act in the same way, but they use other methods to differentiate a threat, since they have no "eyes." There are many ways that your aquarium can be taken care of with coral reefs and coral fish. So long as you choose the right organisms that get along and can tolerate one another, there should not be any problem in the aquarium.
