How do viruses primarily differ from living organisms?

Viruses primarily differ from living organisms in that they cannot carry out metabolic processes on their own. This is a fundamental characteristic of viruses; they lack the necessary cellular machinery to perform metabolic functions such as energy production and biosynthesis. Instead, viruses depend on host cells to replicate and produce their components. Once a virus infects a host cell, it hijacks the host's metabolic processes to reproduce and assemble new viral particles.

Living organisms, on the other hand, have a complete set of cellular machinery that allows them to reproduce independently, utilize nutrients, and carry out various metabolic functions necessary for life. This distinction is crucial in microbiology, as it shapes our understanding of how viruses interact with living systems and the implications of viral infections on health.