Those creatures that exhibit the essential features of life are referred to as living entities. The capacity to grow, reproduce, take in and utilise energy, excrete waste, react to the environment, and possess an ordered structure that is more complicated than that of non-living entities are some of these traits.
Movement is another trait that is often mentioned as being essential to life; yet, many living creatures, such as trees, mushrooms, barnacles, and coral, are unable to move at any point in their lives. On the other hand, viruses represent a unique category of organisms that are not considered to be living things. Viruses are considered to be creatures despite the fact that they are unable to reproduce or take in their own source of energy. This is due to the fact that viruses still possess genetic data and have evolutionary lineages. In addition, viruses are able to reproduce inside the cells of their hosts and may survive independently of their hosts, despite the fact that they are inert when they are not within their hosts. Scientists are the only people who believe viruses to be alive because they regard the capacity to multiply to be the single most important quality of life.