Virus is a microscopic organism which lives in a living organism for its existence. It can be categorised as both living and non-living depending on the characteristics it exhibit then.
Virus cannot perform any life process(e.g reproduction, e.t.c) without being in a living cell called HOST i.e virus will become non-living thing and won't be able to perform any life process without a living host.
Virus do not die but rather hibernate and starts their normal operation once they are in contact with a living host.
Viruses are very small that they can only be seen by electron microscope, even smaller than bacteria.
Virus replicates inside living cell. Some viruses are beneficial while others are detrimental to human health. Examples of virus include: polio virus, rabies virus, corona virus, hanta virus, e.t.c