Affirm is a financial technology service that offers buy now, pay later solutions to consumers. It allows users to make purchases online or in-store and pay for them over time through installment plans. With Affirm, customers can choose from various repayment plans typically at the time of checkout, providing flexibility in managing their budgets. The platform also provides transparent pricing with no hidden fees or late fees, making it a popular choice for consumers looking for an alternative to traditional credit options.