Respiration in plants is a passive process, which means the breathing occurs on a cellular level, not by active muscular movements. Respiration for animals is an active process of inhaling oxygen and exhaling carbon dioxide using muscular movements and energy.
Plants do not possess a well-developed respiratory system like most animals. Plants mainly breathe through pores in their leaves called stomata.
Plants take in carbon dioxide and give out oxygen, whereas animals take in oxygen and give out carbon dioxide.
Unlike plants, most animals use a circulatory system to transport respiratory gases to different parts of the body.