Just like Contact Buttons, Opportunity Tabs allow you to display GHL Forms, Surveys or Funnels or even an external website inside of the Opportunity itself.
These forms can be prefilled with the contact's information. This can be used to embed a form that will start a workflow, or display an external integration.
Go High Level recently released the ability to associate additional contacts with opportunities.
We have now adapted our system to allow you to have Opportunity Tabs for these additional contacts as well.