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# AWS SNS (Simple Notification Service)
Amazon Simple Notification Service (AWS SNS) is a fully managed publish/subscribe messaging service.
What is pub/sub messaging service? As per ChatGPT the following can be summarized:
{% hint style="info" %}
Apache **KAFKA** is also an example of such messaging service
{% endhint %}
It enables to create decoupled applications i.e., Publishers do not need to know the details of the subscribers, and subscribers do not need to know who publishes messages.
It enables the distribution of messages and notifications across different channels such as email, SMS, HTTP/HTTPS, push notifications etc. AWS SNS uses a publish-subscribe model, where publishers send messages to topics, and subscribers receive those messages based on their interest in specific topics i.e., **subscribers will receive notifications for what they have subscribed for.**
A Topic ARN is a unique identifier for an SNS topic within AWS. It’s used to address and target specific topics when publishing messages. Topic ARNs are essential for routing messages to the appropriate subscribers and play a key role in the access control policies that define who can publish and subscribe to specific topics.
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