What's the difference between AzureChatClient and AzureOpenAIChatCompletionService?

[grafanaKibana]

What’s the difference between AzureChatClient and AzureOpenAIChatCompletionService?

I replaced ChatCompletionService with AzureChatClient, but it didn’t seem to have any effect in my app.

To clarify, I’m not calling either of them directly, I’m using plugins created from the Prompt Templates.