Referral or affiliate?

Same link, different deal.

Both pay someone for bringing in a customer. Who that someone is, and what the rules expect of them, is where they split.

Side by side

Referral programs and affiliate programs compared. Swipe sideways on a small screen.
 Referral programAffiliate program
Who it's forCustomers who already use the product.People who promote products, often through a site, channel or newsletter.
How you joinUsually automatic once you have an account.An application the company can turn down.
What you getCredit, a discount, points or a cash bonus, often for both people.A commission on sales or signups, usually for the affiliate only.
Where you can shareOften limited to people you know. Many programs ban coupon sites and ads.Spelled out in the affiliate agreement.
LimitsOften a yearly cap on rewards.Usually no cap, but a minimum balance before payout.
Telling peopleSay you get something if they sign up.A clear disclosure right next to the link.
TaxesCash rewards, especially from banks and brokerages, can be taxable.Commission is income.

The rule that covers both

If you get something for recommending a product, the Federal Trade Commission expects you to say so when you post about it publicly. A small ride credit counts, and so does a big commission.

Which one is this site about?

The first column: offers for customers and the friends they bring along.