Thanks for posting your question in the Microsoft Q&A forum.
I think you mean powered by GPT-4. It means that the responses you receive are generated using the advanced capabilities of GPT-4.Both ChatGPT-4 and CoPilot using GPT-4 and support full functionality of GPT-4 but they have different trained model. As CoPilot has different version for different tools with different content to train their models.
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