The various grouping levels or ranks in classification are known as taxonomic categories.
The levels or groups are known as a taxon.
A taxon refers to a group of similar and genetically related individuals having certain characters different from other groups.
There are basically, seven major categories like kingdom, phylum, class, order, family, genus and species.
Kingdom- The kingdom is the highest category in biological classification. It is a group of closely related organisms.
Phylum- is a level of classification below Kingdom and above Class.
Class- is a group of related orders.
Order- is a group of related families which exhibit a few similar characters.
Family- is a group of the related genus.
Genus- is a group of related living things (as plants or animals) that ranks below the family.
Species- is a group of actually or potentially inbreeding population reproductively isolated from other such groups. It is the lowest taxonomic characteristics.