This is a category containing comparison articles. A comparison article deals with similar topics where differences are displayed and examined. The comparison can deal with any notable subjects such as abstract theories, concrete objects, intangible phenomena, etc.
Comparisons are useful to convey information about different topics to show what makes each topic unique in its own right while showing the inherent similarities. There is a plethora of comparison styles, so there is no strict format to follow. Just make sure a comparison is made.