Under what conditions do competitive relations arise between organisms?

Competitive relationships between organisms of the same or different species arise if their life requires the same conditions, the same resource For example, food, breeding grounds, shelter, etc. Competition is active and passive. Active – when one species suppresses the action of another, for example, the release of poison, deterrent chemicals, warning sounds. Passive – when just the same resource (grass) is used by different species of the same biocenosis (elk and hare).