logging options in boto3 set_stream_logger

The AWS SDK for Python (Boto3) uses the standard Python logging module, so you're most likely to find helpful insights by referencing the official Python docs as well as articles that cover logging generally.

Here's a direct link to the detail on pre-defined logging levels described in the Python docs.

The Python docs don't really provide guidance on when the various log levels should be used. One resource I've found personally useful in understanding logging best practices—including what log levels mean—is the article, "The 10 commandments of logging".