Axial coding is the second stage of coding in grounded theory methodology that involves categorizing the data into more specific and interconnected categories. It is used to identify relationships between the categories identified during open coding and to develop a more comprehensive understanding of the phenomenon being studied. The grounded theory tradition involves constantly comparing emergent themes in research data with each step of coding further categorizing those themes. Axial coding is part of the three-step coding process: open, axial, and selective coding.

During axial coding, researchers examine their open codes and look for relationships between them. They then develop categories that reflect these relationships and explore how they connect to each other. These new categories are often referred to as "subcategories" or "properties" of the original categories, and they help to refine and expand upon the initial coding.

When it comes to breaking down the process of axial coding, there are four different subcategories that can be separated. These include dividing categories into their own sections or codes as well as describing how data is coded and linked together using grounded theory procedures in order for researchers/reporters alike to have a better understanding on what they’re studying when doing research about a particular subject matter.

When refined, axial coding can be described as a "hub-and-spoke" model of categories. With key categories as the hub and subcategories as the spokes.

Overall, axial coding helps researchers to develop a more detailed and nuanced understanding of the data by exploring the relationships between different concepts and themes. This allows for the development of a more robust grounded theory that can be used to explain the phenomenon being studied.