**3. Classification of viruses**

#### **3.1 ICTV classification**

The ICTV evolves the current classification system and wrote guidelines that put a bigger weight on certain virus properties to maintain family consistency. A unified taxonomy has been accepted. Solitary a little part of the entire variety of viruses has been studied. Till 2019 ICTV explained 9 kingdoms, 4 realms, 2 subphyla, 16 phyla, 36 classes, 55 orders, 9 suborders, 168 families, 10 sub-families, 1421 genera, 68 subgenera and 6589 species of viruses [9].

The general taxonomic structure of ranges of taxon and the suffixes used in taxonomic names are mentioned under. Till 2019, the ranks of sub realm, subkingdom and subclass are unemployed whereas all ranks are in usage.

Realm (*−viria*), Subrealm (*vira*), Kingdom (*−virae*), Subkingdom (*−virites*), Phylum (*−viricota*), Subphylum (*−viricotina*), Class (*−viricetes*), Subclass (*−viricetidae*), Order (*−virales*), Suborder (*−virineae*), Family (*−viridae*), Subfamily (*−virinae*), Genus (*−virus*), Subgenus (*−virus*) [10].
