The Referral module gives your Partners the ability to send you prospective Leads/Referrals. You can then choose to work the Referrals yourself or send them to other Partners as Leads. The Partner can then convert the Leads to Deals or close them if there's no business. It also allows you to track commissions and gives the referring Partners full visibility into the progress/status of their Referrals throughout the sales cycle.
Submitting a Referral:
Partners submit Referrals by completing your Referral form, and the Internal recipients listed in your Referral Email Notifications are notified.
Referral Form
Accepting/Rejecting Referrals:
The Internal User can accept or reject the Referral by updating the Referral's Status. The Status field is also used to track commission payments. Any updates made to the Referral will trigger a notification to the referring Partner.
Referral Status Field
Referral Status Field - Commission Payment
The referring Partner can also log in at any time to track the progress of their Referrals. 
Referral Details Page - Status
Sending Referrals to Partners:
Another way to accept Referrals is to send them to Partners as Leads. 
Referral Details Page
The Partner can then convert the Lead to a Deal or close it if there's no business opportunity.
Lead Details Page
If converted to a Deal, you'll see the Referral details on the Deal details page, and you'll be able to run custom reports that include the Referral commission status/amount fields.
Deal Details Page
Deals Report - Commission Status and Amount
Salesforce & HubSpot Referral Integrations:
If the Referral integration with Salesforce is enabled in your portal, the Referral will create a corresponding Lead in Salesforce CRM. This can be configured to happen automatically or on a manual basis. Learn more about this topic here: Salesforce Integration: Referral - Overview.
Referral Details Page - Salesforce Actions Menu
If the Referral integration with HubSpot is enabled in your portal, the referral will create a corresponding Deal in HubSpot. This can be configured to happen automatically or on a manual basis. Learn more about this topic here: HubSpot Integration: Referral - Overview.
Referral Details Page - HubSpot Actions Menu