Notification Services are systems designed to send alerts or updates to users about specific events or changes. These notifications can be delivered through various channels, such as email, SMS, or mobile app alerts. They help keep users informed about important information, like reminders, news updates, or changes in status. These services are commonly used in applications like social media platforms, e-commerce sites, and productivity tools. For example, a calendar app might use Notification Services to remind users of upcoming events, while a shopping website could notify customers about sales or order status updates.