These two messaging services get compared constantly. The distinction is pull vs push, one consumer vs many.
Queue vs pub/sub
SQS is a queue: messages wait until one consumer group pulls and processes them — for decoupling and buffering work. SNS is pub/sub: a message is pushed to all subscribers at once — for fan-out notifications. Need to buffer work for a worker? SQS. Need to notify many systems from one event? SNS. They combine well: SNS fans out into multiple SQS queues.
Test yourself
You need to decouple a web tier from a backend worker so requests are buffered and processed one at a time at the worker’s pace. Which service?
- Amazon SNS
- Amazon SQS
- Amazon EventBridge
- Amazon Kinesis
👉 Click to reveal the answer & explanation
Correct answer: B. SQS buffers messages in a queue for a consumer to pull and process at its own pace — classic decoupling. SNS (A) pushes to all subscribers at once; EventBridge (C) routes events by rules; Kinesis (D) is for streaming data.
Related topics
Amazon SQS · Amazon SNS · Amazon EventBridge
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