Ecological interactions describe how organisms relate to each other and their environment. The main types include competition, where species vie for limited resources; predation, in which one organism hunts another; mutualism, where both species benefit; commensalism, where one benefits without affecting the other; and parasitism, where one organism benefits at the expense of another. These interactions regulate population sizes, maintain ecosystem balance, and drive evolutionary adaptations. Understanding these relationships is critical for conservation efforts, habitat restoration, and ensuring the stability of natural ecosystems in the face of environmental changes.