A Contact Stage describes where you are currently at with your client, for example: Contacted, Qualified, Ready to Purchase, etc.
Contact stage can be used as a search criteria when searching your Contacts.
Related articles:
How can I manage my Contact Source and Contact Stage lists?
What is a Contact Source?
What is a Contact Stage?
You can build your own list of Contact Stages to suit your needs. The list is flexible and Stages can be added, edited or deleted any time.