On the Contacts page you can see contacts associated with a deal. If available, you will also be able to see their name, title, firm, email, and cell phone. You can use the search bar, sort, and group tools to look for specific contacts. On this page you can also create, assign, and delete contacts.

In order to assign a contact to a deal, the contact must already exist. See below how to create a contact.
To assign a contact:
When contacts are created, they will automatically be assigned to the given deal. The contact you create will also be added to the global list of contacts for a given deal's portfolio.