With CRM Pro, there are pre-existing categories such as seller, buyer, and showing agent. You can also create your own categories. Each contact can be tagged with multiple categories. You can use the "Quick Search" feature to filter contacts by category. An example would be creating a category that is the name of a specific neighborhood to tag all your buyers who want to purchase a house there. When one becomes available, you can quickly look them up using the "Quick Search" feature and let them know.
How to create a custom category:
How to filter your contacts by category: