Retrieve the current site ID.

Retrieves the current network ID.

Determines whether the current request is for an administrative interface page.

Whether the current request is for a site’s administrative interface.

If Multisite is enabled.

Whether the current request is for the network administrative interface.

Determines whether we are currently handling an Ajax action that should be protected against WSODs.

Determines whether we are currently on an endpoint that should be protected against WSODs.

Determines if SSL is used.

Whether the current request is for a user admin screen.