A feed is like a notification that communicates information to an add-on or to an external service that the add-on integrates with, each time a visitor successfully submits your form.
Whereas a notification will fire an email off to a destination of your choice each time a Gravity Forms submission is completed, a 「feed」 is set-up within an add-on in order to define the way your form will notify the add-on (and potentially an external service) of a submission.
The reason to do this is because you want the external service to do something with it, such as:
send information to a customer management system in order to create a new customer record. E.g. Agile CRM Add-On or ActiveCampaign Add-On.
send information to a payment gateway in order to generate a charge. E.g. Paypal Payments Standard Add-On or 2Checkout Add-On.
send information to a ticketing service to initiate a support request. E.g. Help Scout Add-On.
send information to a communication service to generate a message in that service. E.g. Slack Add-On.
send file information to a storage service. E.g. Dropbox Add-On.
In general when setting up a feed for an external service, you will have to setup the following:
configure an API key or unique identifier that allows the external service to securely identify your submissions as coming from you. This is usually done within the Add-On Settings.
identify the form you want to use to send the information.
map the form fields to the external service fields you want to populate. For example, identifying which phone number field on your form is going to be sent to a CMS service to create a new custom record.
if needed, set any conditional logic you need in order to describe the conditions you want the submission to be sent using your feed. For example, you may only want the customer details to be sent using the 「new customer」 feed when a form field is set to 「new customer」, else you will want to fire the 「update customer」 feed. For information on enabling conditional logic for a feed, please see this article.
For specific instructions on setting up your feeds, refer to the user guide for each add-on.
Note: A feed must be present and active at the time of form submission in order to send information to the external service. Entries created without an active feed will not be sent to the service. Creating a feed afterwards will not process any entries previously submitted.
Tip: If you cannot find an Add-On that supports the specific external service you want to integrate your form with, then try the Zapier Add-On, which is a service expressly designed for providing hundreds of integrations with other services.