To make it easier to receive the notifications you're interested in, you can mark notifications as read, subscribe and unsubscribe from notifications, and watch and unwatch repositories.
If you receive web notifications, you can mark notifications as read without removing them. If an update is made to the conversation, you'll receive a new notification.
You can subscribe to individual conversations that interest you even if you're not watching the repository where the conversation is occuring. If you're no longer interested in a conversation, you can unsubscribe from any future notifications.
You can watch a repository to receive notifications for new pull requests and issues that are created. You can also unwatch a repository if you no longer want to receive notifications for that specific repository.
You can get an overview of all the repositories you're watching so that you can easily remove any you're no longer interested in receiving notifications for.