AppServer
A third-party Application Server that delivers notifications to client applications via Push.

Bridging
Using a third party or proprietary network in order to deliver Push notifications to an App. This may be preferred for mobile devices where such a network may improve battery life or other reasons.

Channel
A unique route between an AppServer and the Application. May also be referred to as Subscription

CHID
The Channel Subscription ID. Push assigns each subscription (or channel) a unique identifier.

Message-ID
A unique message ID. Each message for a given subscription is given a unique identifier that is returned to the AppServer in the Location header.

Notification
A message sent to an endpoint node intended for delivery to a HTTP endpoint. Autopush stores these in the message tables.

Router Type
Every UAID that connects has a router type. This indicates the type of routing to use when dispatching notifications. For most clients, this value will be webpush. Clients using Bridging it will use either gcm, fcm, or apns.

Subscription
A unique route between an AppServer and the Application. May also be referred to as a Channel

UAID
The Push User Agent Registration ID. Push assigns each remote recipient (Firefox client) a unique identifier. These may occasionally be reset by the Push Service or the client.

WebPush
An IETF standard for communication between Push Services, the clients, and application servers.

See: https://datatracker.ietf.org/doc/draft-ietf-webpush-protocol/