The process by which living organisms develop is known as "biological development" or "organismal development." It involves a series of complex biological processes starting from a fertilized ovum, which undergoes cell division and differentiation. This leads to the formation of tissues, organs, and systems that together constitute a mature organism. Development is influenced by genetic information and environmental factors, ensuring that organisms grow and adapt to their surroundings. This process includes stages such as embryonic development, maturation, and eventual growth into adulthood, which can vary significantly across different species.