An affiliate is a person or business that promotes products or services of another company in exchange for a commission on sales or leads generated through their marketing efforts. Affiliates typically use various online platforms, such as blogs, social media, websites, and email newsletters, to reach their audience and encourage them to make purchases or take actions that benefit the company they represent.

The relationship between the affiliate and the company is usually governed by an affiliate program. This program outlines the terms, including commission rates, payment methods, and promotional guidelines. Affiliates can help companies expand their reach and gain new customers, while also benefiting financially from the sales they help generate. It's a win-win situation for both parties involved.