Industry Types help you segment your contacts by industry. In some cases this field may not be completely relevant, in which case you can even decide to turn it off from within the Custom Labels Tab inside Settings > Contact Settings. 

You need to be an administrator to perform this task. 

Click on the Settings Tab > Contact Settings > Industry Types

Dimension CRM has most of the universally accepted Industry segments already defined in the system. You can use the pencil icon to edit one or click on the red cross icon to delete. 

You can also use the New Industry Type form on the right hand side to create a new industry type.