A paywall is a digital barrier used by websites and online publishers to restrict access to certain content, such as news articles, research papers, or multimedia resources. To view content behind a paywall, users are typically required to pay a fee, subscribe, or register. Paywalls help content creators and publishers generate revenue by limiting free access and encouraging users to support their work financially. There are different types of paywalls, including hard paywalls that block all content unless paid for, and soft or metered paywalls that allow limited free access before requiring payment.