Virus classification

Virus classification is the way viruses are put into groups by scientists.
There are many different kinds of viruses. Scientists classify viruses to make it easier to learn about them. Classification also helps scientists to remember viruses and the diseases they cause. The International Committee of Taxonomy of Viruses (ICTV) is in charge of virus classification. 
Sometimes different viruses have things in common. This is used in classification. For example, if they are made from DNA and protein, or RNA and protein. Other things that are taken into account are the size and shape of the viruses and the diseases they cause.
Similar viruses are first put into "families". Each family has a name. This family name always ends with ""-viridae". For example, rotaviruses are in the "Reoviridae" family and herpes viruses are in the "Herpesviridae" family.
Viruses in any one family that are almost the same are then put in a smaller group called a "genus".
Another way of classifying viruses is called the Baltimore Classification. This is different from the ICTV one. Some scientists prefer the Baltimore Classification because it is based on how viruses grow in cells.