The term "**Idempotent**" refers to any action that can be performed more than one time ==without causing side effects==. This has implications is system design (particularly [[Distributed Systems]]) and coding, where you may have issues sending a particular message, and you'd like to be able to simply re-send the message, but if two messages arrive saying the same thing they need to be functionally equivalent to one message.
| Idempotent | NOT Idempotent |
| ----------------------------------- | ---------------------------- |
| Set Switch A to `on` | Toggle Switch A |
| Request ABC123 received for 3 units | Request received for 3 units |
| Set Daily_Sum = `6` | Add `1` to Daily_Sum |
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# More
## Source
- Fireship, originally,
- Conversation with Gemini