The competition exclusion principle

What is the competition exclusion principle? Definition:

The Competitive exclusion principle says: Two different species can not occupy the same ecological niche. Such a situation exists when two species are in direct competition with each other in at least one essential factor (water, food or habitat). In the long run one of two kinds, as a rule more competitive, will prevail over other species and will displace them from an ecological niche.
As a result of the competition exclusion principle it often happens in competing species contention resolution, Rivalry may look like this: Species evade other ecological niches by feeding on other food (such as insects instead of grains), changing their habits (for example, diurnal instead of nocturnal), or changing their habitat (e.g., dense forests instead of open grasslands). Such processes, of course, are protracted and a deviation into other ecological niches is not always possible. Therefore, under competitive pressure, there may well be a definitive displacement of the more competitive type.
The interspecific competition avoidance and the associated avoidance into other ecological niches is thus an essential factor for the enormous biodiversity on earth. Adaptive radiation can also be combined with the competition exclusion principle. However, it is necessary to differentiate clearly, as species starts with intraspecific competition and the competitive exclusion principle concerns only extraneous competition.