!!! Overview
[{$pagename}] is the [client] within the [Web Authentication API] [specification] is an intermediary [entity] typically implemented in the user agent (in whole, or in part). Conceptually, it underlies the [Web Authentication API] and embodies the [implementation] of the internal methods. 

[{$pagename}] is responsible for both marshalling the inputs for the underlying [authenticator] operations, and for returning the results of the latter operations to the [Web Authentication API]'s callers.

[{$pagename}] runs on, and is distinct from, a [WebAuthn Client Device].

[{$pagename}] was most closely related to the [CTAP2 Platform Host] and referred to simply as the "host" in earlier [specifications]

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]