An affinity group is made up of people who support each other and help everyone feel included. Members of these groups usually share certain characteristics or experiences that aren’t common in their company. These groups are sometimes called employee resource groups (ERGs) or other names, depending on the workplace.
Interest groups are more casual and are for people who like the same things, like reading or running. These groups might not be officially part of your company’s activities, they’re just for fun and sharing hobbies.