A paywall is a feature of a website or other technology that requires payment from users in order to access additional content or services. Paywalls are increasingly being used to restrict access to content on a website to those who pay for it.
Paywalls represent a shift in terms of Web content, which has traditionally been free for users and paid for by advertising. However, as part of the flood of content from print media to the Web and mobile devices, the paywall has become an important tool for providing revenue flows to some businesses, especially news sites.
Techopedia explains Paywall
Paywalls can vary in design. Some experts refer to "hard" or "soft" paywalls that are more or less restrictive to users. Some hard paywalls are set up so that users cannot gain any access to a site without payment. Soft paywalls, on the other hand, may allow for limited viewing free of charge.