!!! Overview [1] [2]
[{$pagename}] are typically a component of a [Progressive Web Application] and provide a scriptable network [proxy] in the [web] [browser] to manage the web/[HTTP Requests] programmatically. 

[{$pagename}]s lie between the [network] and [device] to supplement the content. 

[{$pagename}] are capable of using the [cache] mechanisms efficiently and allow error-free behavior during offline periods.

[{$pagename}]s are an incredibly powerful, and equally as confusing, technology behind a [Progressive Web Application]

[{$pagename}] is a script that your [browser] runs in the background, separate from a [Web] page, opening the door to features that don't need a [Web] page or user interaction.

!! Properties of Service Workers
* Trigger and keep alive by the relationship to the events, not by the documents
* Generic in nature
* Event-driven with time limit scripting contexts and running at the origin
* With natural endpoints for a wide range of runtime services
* Have a [state]
* With a script [URL]
* Containing registration
* Allocated ID or [UUID]
* With [life cycle] events
* Have script resource map
* Can skip waiting for the flags!! Benefits of [{$pagename}]s
* Capable of handling the push [notification] easily
* [Synchronization] of [data] in the background
* Capable of responding to the resource requests originate elsewhere
* Receive centralized updates!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]
----
* [#1] - [What are Progressive Web Apps?|http://blog.ionic.io/what-is-a-progressive-web-app/|target='_blank'] - based on information obtained 2017-08-02- 
* [#2] - [Progressive_web_app|Wikipedia:Progressive_web_app|target='_blank'] - based on information obtained 2017-08-02-