Definition: In the context of web development, a "subscriber" is someone who receives notifications or updates from an application or website. This can include emails, push notifications, or other types of digital content that is delivered to their device. Subscribers are often referred to as "readers," and they typically use these services to stay up-to-date on the latest information or events related to the service or product being used. There are many different ways that a subscriver can subscribe to an application