Merge pull request #281934 from kevinguo-ed/update-overview

Updated overview

Author: v-dirichards

articles/azure-web-pubsub/overview.md

@@ -1,61 +1,71 @@
 ---
 title: What is Azure Web PubSub service?
-description: Better understand what typical use case scenarios to use Azure Web PubSub, and learn the key benefits of Azure Web PubSub.
-author: yjin81
-ms.author: yajin1
+description: Better understand what typical use cases and app scenarios Azure Web PubSub service enables, and learn the key benefits of the service.
+author: kevinguo-ed
+ms.author: kevinguo
 ms.service: azure-web-pubsub
 ms.topic: overview 
-ms.date: 07/12/2024
+ms.date: 07/26/2024
 ---
 
 # What is Azure Web PubSub service?
 
-The Azure Web PubSub Service makes it easy to build real-time messaging web applications using WebSockets and the publish-subscribe pattern. This real-time functionality allows publishing content updates between server and connected clients (for example, a single page web application or mobile application). The clients don't need to poll for the latest updates, or submit new HTTP requests for updates.
+Azure Web PubSub Service makes it easy to build web applications where server and clients need to exchange data in real-time. Real-time data exchange is the bedrock of certain time-sensitive apps developers build and maintain. Developers have used the service in a variety of applications and industries, for exmaple, in chat apps, real-time dashboards, multi-player games, online auctions, multi-user collaborative apps, location tracking, notifications, and more. 
 
-This article provides an overview of the Azure Web PubSub service.
+With the recent surge in interest in AI, Web PubSub has become an invaluable tool to developers building AI-enabled applications for token streaming. The service is battle-tested to scale to tens of millions of concurrent connections and offers ultra-low latency. 
+
+When an app's usage is small, developers typically opt for a polling mechanism to provide real-time communication between server and clients - clients send repeated HTTP requests to server over a time interval. However, developers often report that while polling mechanism is straightforward to implement, it suffers three important drawbacks. 
+- Outdated data. 
+- Inconsistent data. 
+- Wasted bandwidth and compute resources.
+
+These drawbacks are the primary motivations that drive developers to look for alternatives. This article provides an overview of Azure Web PubSub service and how developers can use it to build real-time communication channel fast and at scale.
 
 ## What is Azure Web PubSub service used for?
 
-Any scenario that requires real-time publish-subscribe messaging between the server and clients or among clients, can use the Azure Web PubSub service. Traditional real-time features that often require polling from the server or submitting HTTP requests, can also use the Azure Web PubSub service.
+Any app scenario where updates at the data resource need to be delivered to other components across network can benefit from using Azure Web PubSub. As the name suggests, the service facilities the communication between a publisher and subscribers. A publisher is a component that publishes data updates. A subscriber is a component that subscribes to data updates. 
 
-The Azure Web PubSub service can be used in any application type that requires real-time content updates. We list some examples that are good to use the Azure Web PubSub service:
+Azure Web PubSub service is used in a multitude of industries and app scenarios where data is time-sensitive. Here's a partial list of some common use cases. 
 
-* **High frequency data updates:** gaming, voting, polling, auction.
-* **Live dashboards and monitoring:** company dashboard, financial market data, instant sales update, multi-player game leader board, and IoT monitoring.
-* **Cross-platform live chat:** live chat room, chat bot, on-line customer support, real-time shopping assistant, messenger, in-game chat, and so on.
-* **Real-time location on map:** logistic tracking, delivery status tracking, transportation status updates, GPS apps.
-* **Real-time targeted ads:** personalized real-time push ads and offers, interactive ads.
-* **Collaborative apps:** coauthoring, whiteboard apps and team meeting software.
-* **Push instant notifications:** social network, email, game, travel alert.
-* **Real-time broadcasting:** live audio/video broadcasting, live captioning, translating, events/news broadcasting.
-* **IoT and connected devices:** real-time IoT metrics, remote control, real-time status, and location tracking.
-* **Automation:** real-time trigger from upstream events.
+|Use case              |Example applications   |
+|----------------------|----------------------|
+|High frequency data updates | Multi-player games, social media voting, opinion polling, online auctioning |
+|Live dashboards and monitoring | Company dashboard, financial market data, instant sales update, game leaderboard, IoT monitoring |
+|Cross-platform chat| Live chat room, AI-assisted chatbot, online customer support, real-time shopping assistant, messenger, in-game chat |
+|Location tracking | Vehicle asset tracking, delivery status tracking, transportation status updates, ride-hailing apps |  
+|Multi-user collaborative apps | coauthoring, collaborative whiteboard and team meeting apps |
+|Cross-platform push notifications | Social media, email, game status, travel alert | 
+|IoT and connected devices | Real-time IoT metrics, managing charging network for electric vehicles, live concert engagement |
+|Automation | Real-time trigger from upstream events | 
 
 ## What are the benefits using Azure Web PubSub service?
 
 **Built-in support for large-scale client connections and highly available architectures:**
 
-The Azure Web PubSub service is designed for large-scale real-time applications. The service allows multiple instances to work together and scale to millions of client connections. Meanwhile, it also supports multiple global regions for sharding, high availability, or disaster recovery purposes.
+Azure Web PubSub service is designed for large-scale, real-time applications. With a single Web PubSub resource, it can scale to 1 million concurrent connections, which is sufficient for most cases. When multiple resources are used together, the service allows you to scale beyond 1 million concurrent connections. Meanwhile, it also supports multiple global regions for sharding, high availability, or disaster recovery purposes.
 
 **Support for a wide variety of client SDKs and programming languages:**
 
-The Azure Web PubSub service works with a broad range of clients. These clients include web and mobile browsers, desktop apps, mobile apps, server processes, IoT devices, and game consoles. Since this service supports the standard WebSocket connection with publish-subscribe pattern, it's easy to use any standard WebSocket client SDK in different languages with this service. 
+Azure Web PubSub service works with a broad range of clients. These clients include web and mobile browsers, desktop apps, mobile apps, server processes, IoT devices, and game consoles. Server and client SDKs are available for mainstream programming languages, C#, Java, JavaScript, and Python, making it easy to consume the APIs offered by the service. Since the service supports standard WebSocket protocol, you can use any REST capable programming languages to call Web PubSub's APIs directly if SDKs aren't available in your programming language of choice.
 
 **Offer rich APIs for different messaging patterns:**
 
-Azure Web PubSub service is a bi-directional messaging service that allows different messaging patterns among server and clients, for example:
-
-* The server sends messages to individual clients, all clients, or groups of clients that are associated with a specific user or categorized into arbitrary groups.
-* The client sends messages to clients that belong to an arbitrary group.
-* The clients send messages to server.
+Azure Web PubSub service offers real-time, bi-directional communication between server and clients for data exchange. The service offers features to allow you to finely control how a message should be delivered and to whom. Here's a list of supported messaging patterns.
 
+|Messaging pattern              |Details                         |
+|-------------------------------|--------------------------------|
+|Broadcast to all clients | A server sends data updates to all connected clients. |
+|Broadcast to a subset of clients | A server sends data updates to a subset of clients arbitrarily defined by you. |
+|Broadcast to all clients owned by a specific human user | A human user can have multiple browser tabs or device open, you can broadcast to the user so that all the web clients used by the user are synchronized. |
+|Client pub/sub | A client sends messages to clients that are in a group arbitrarily defined by you without your server's involvement.| 
+|Clients to server | Clients send messages to server at low latency. | 
 
 ## How to use the Azure Web PubSub service?
 
 There are many different ways to program with Azure Web PubSub service, as some of the samples listed here:
 
 - **Build serverless real-time applications**: Use Azure Functions' integration with Azure Web PubSub service to build serverless real-time applications in languages such as JavaScript, C#, Java and Python. 
-- **Use WebSocket subprotocol to do client-side only Pub/Sub** - Azure Web PubSub service provides WebSocket subprotocols to empower authorized clients to publish to other clients in a convenience manner.
+- **Use WebSocket subprotocol to do client-side only Pub/Sub** - Azure Web PubSub service provides WebSocket subprotocols to empower authorized clients to publish to other clients in a convenient manner.
 - **Use provided SDKs to manage the WebSocket connections in self-host app servers** - Azure Web PubSub service provides SDKs in C#, JavaScript, Java and Python to manage the WebSocket connections easily, including broadcast messages to the connections, add connections to some groups, or close the connections, etc.
 - **Send messages from server to clients via REST API** - Azure Web PubSub service provides REST API to enable applications to post messages to clients connected, in any REST capable programming languages.