Cichlid is a species. They come from Central and South America (oscars, demsy's, angelfish) African cichlids come from 3 great lakes (Tanganyika, Malawi, Victoria) and the non-lakes.
Though they are from the same species they do not have the same care factors (ph, temp, breeding habits) so it is best not to keep american and african cichlids together.
It is best to have a tank no smaller than 55 gallons for them to thrive. The smaller the tank the more likely they will kill off each other since they are very territorial.
Cichlids are also some of the most beautiful freshwater fish. If your interested in seeing some pic's
www.aquabid.com is a good place to visit.