Explanation:

Box 1: id
id is a unique identifier for the event.
Box 2: eventType
eventType is one of the registered event types for this event source.
Box 3: dataVersion
dataVersion is the schema version of the data object. The publisher defines the schema version.
Scenario: Authentication events are used to monitor users signing in and signing out. All authentication events must be processed by Policy service. Sign outs must be processed as quickly as possible.
The following example shows the properties that are used by all event publishers:
[
{
"topic": string,
"subject": string,
"id": string,
"eventType": string,
"eventTime": string,
"data":{
object-unique-to-each-publisher
},
"dataVersion": string,
"metadataVersion": string
}
]
Reference:
https://docs.microsoft.com/en-us/azure/event-grid/event-schema

Explanation:

B: The allkeys-lru policy evict keys by trying to remove the less recently used (LRU) keys first, in order to make space for the new data added. Use the allkeys-lru policy when you expect a power-law distribution in the popularity of your requests, that is, you expect that a subset of elements will be accessed far more often than the rest.
C: volatile-lru: evict keys by trying to remove the less recently used (LRU) keys first, but only among keys that have an expire set, in order to make space for the new data added.
Note: The allkeys-lru policy is more memory efficient since there is no need to set an expire for the key to be evicted under memory pressure.
Reference:
https://redis.io/topics/lru-cache

Explanation:

Box 1: NotificationHubClient
Box 2: NotificationHubClient
Box 3: CreateClientFromConnectionString
// Initialize the Notification Hub
NotificationHubClient hub = NotificationHubClient.CreateClientFromConnectionString(listenConnString, hubName); Box 4: SendWindowsNativeNotificationAsync Send the push notification.
var result = await hub.SendWindowsNativeNotificationAsync(windowsToastPayload); References:
https://docs.microsoft.com/en-us/azure/notification-hubs/notification-hubs-push-notification-registration- management
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/app-service-mobile/app-service-mobile- windows-store-dotnet-get-started-push.md