The two classification groups used in a scientific name are:

1. Genus: This is the first part of the scientific name and represents a group of closely related species. It is always capitalized.

2. Species: This is the second part of the scientific name and designates a specific kind of organism within the genus. It is always written in lowercase.

For example, the scientific name for humans is *Homo sapiens*. *Homo* is the genus and *sapiens* is the species.