The world lives at a time when it witnessed an accelerated spread of strong viruses such as HIV, swine flu, sracing and Lhasa fever, and the prominent biologist and the famous scientific writer, Dorothy H Crawford, takes us on an amazing journey to explore the world of these small creatures with great danger. It provides us with an interesting and comprehensive picture of viruses, starting with its discovery and attributes, and ending with their classifications and reproduction mechanisms, reviewing the ways that spread and interact with other living organisms. The book is characterized by an easy -to -understand manner, as it avoids complex artistic terms, provides a balanced mixture of scientific information and practical considerations, which makes it suitable for all readers, and opens a new horizon for understanding virus in an interesting and interesting way.