A push notification is a short, clickable message sent directly to users' devices, providing timely updates on new features, unread messages, or special offers, which can be highly effective and engaging marketing tools if done well, but risk being irritating if not. Targeted news items, behavior-based messages, upgrades, and updates that add value to users are examples of push notifications that inspire engagement. Mobile push notifications appear on mobile device home screens and serve various purposes, including alerting users to new features or sales promotions, while social media apps use them to increase user engagement. Web push notifications are sent through desktop or mobile web browsers and resemble mobile push notifications, with a recommended frequency varying depending on marketing goals.