Why is virus not included in microorganism?

Answer 1

Because a virus is not any kind of an organism, its only part of one.

Its not alive ... its just information ... that uses a living thing (some organism) to replicate itself.

Answer 2

Viruses are not considered microorganisms because they lack many characteristics of living organisms, such as the ability to reproduce on their own or carry out metabolic processes. They require a host cell to replicate and are often seen as biological entities rather than living organisms.