Paywall
A paywall is a method of restricting access to content via a paid subscription. Beginning in the mid-2010s, newspapers started implementing paywalls on their websites as a way to increase revenue after years of decline in paid print readership and advertising revenue. In academics, research papers are often subject to a paywall and are available via academic libraries that subscribe.
Paywall
Three high level models of paywall have emerged: "hard paywalls" that allow no free content and prompt the user straight away to pay in order to read, listen or watch the content, "soft paywalls" that allow some free content, such as an abstract or summary, and "metered paywalls" that allow a set number of free articles that a reader can access over a specific period of time, allow more flexibility in what users can view without subscribing.