An affiliate is a site or marketer that earns money from casinos by referring new customers through tracked links. Payment may be a one-off fee per customer or a share of the casino's revenue from them.
Affiliates are a large part of how online casinos are marketed. GB-licensed operators are responsible for their affiliates' marketing, which must follow advertising rules, including not appealing to under-18s and not presenting gambling as a way to make money.
Slots Games is funded by a single affiliate link to a UK-licensed casino, and that never shapes what we publish. When reading any site that reviews casinos or games, it is worth checking whether it earns from the links it shows and whether figures such as RTP come from the games themselves.