What are the different logging levels in Magento?

Question

I am disabling logging to increase performance, and in core_config_data I see dev/log/active and system/log/active

What is the difference?

Answer 1

Configuration system/log/active is related to logging in system.log and dev/log/active is related to debug/development log normally used with SetEnv MAGE_IS_DEVELOPER_MODE "true"

References here.