Docs: Expand Details section (#1109)

Expands the overview section with language that is slightly-technical
but not in-the-weeds to try to explain the nuance between a playground,
most local apps (pre-Playground 😏 ) and a traditional web server.

## What problem is it solving?

Trying to distill Playground under-the-hood and how it differs from the
WordPress you might now.

## How is the problem addressed?

Humor can be a helpful catalyst as the brain tries to understand new
concepts, so can a few details that might answer some common questions 😄

packages/docs/site/docs/01-start-here/02-overview.md

@@ -25,3 +25,19 @@ The content you create is limited to the Playground on your device and disappear
 ## And, yes it's safe
 
 Overall, WordPress Playground provides a risk-free environment for beginners to learn and get hands-on experience with WordPress. It helps you to gain confidence and knowledge before making changes to your live website.
+
+## What makes Playground different from running WordPress on a web server or local desktop app?
+
+Web applications like WordPress have long-relied on server technologies [to run logic](https://wordpress.github.io/wordpress-playground/architecture/wasm-php-overview) and [to store data](https://wordpress.github.io/wordpress-playground/architecture/wordpress#sqlite).
+
+Using those technologies has meant either running an web server connected to the internet or using those technologies in a desktop service or app (sometimes called a "WordPress local environment") that either leans on a virtual server with the technologies installed or the underlying technologies on the current device.
+
+**Playground is a novel way to stream server technologies -- and WordPress _(and WP-CLI)_ -- as files that can then run in the browser.**
+
+### _Streamed_, not served.
+
+The WordPress you see when you open Playground in your browser is a WordPress that should function like any WordPress, with [a few limitations](https://wordpress.github.io/wordpress-playground/limitations) and the important exception that it's not a permanent server with an internet address which will limit connections to some third-party services (automation, sharing, analysis, email, backups, etc.) in a persistient way.
+
+The loading screen and progress bar you see on Playground includes both the streaming of those foundational technologies to your browser and configuration steps [(examples)](https://wordpress.github.io/wordpress-playground/blueprints-api/examples) from [WordPress Blueprints](https://github.com/WordPress/blueprints-library), so that a full server, WordPress software, Theme & Plugin solutions and configuration instructions can be streamed over-the-wire.
+
+While many WordPress solutions may require internet connectivity to interact with social networks, live feeds and other internet services, those kind of connections [could be limited in Playground](https://wordpress.github.io/wordpress-playground/architecture/wasm-php-overview/#networking-support-varies-between-platforms). However, by enabling network connectivity in the Customize Playground settings modal [(example URL w/ query parameter)](https://playground.wordpress.net/?networking=yes), you can mostly wire-up internet connectivity to the WordPress in Playground.