The order of classification of organisms, from broadest to most specific, is:

1. Domain: The broadest category, encompassing all life. There are three domains: Bacteria, Archaea, and Eukarya.

2. Kingdom: A large group of related organisms within a domain. Examples include Animalia, Plantae, Fungi, and Protista.

3. Phylum: A group of closely related classes.

4. Class: A group of closely related orders.

5. Order: A group of closely related families.

6. Family: A group of closely related genera.

7. Genus: A group of closely related species.

8. Species: The most specific level, defining a group of organisms that can interbreed and produce fertile offspring.

This system is called hierarchical classification and is based on the shared characteristics of organisms.