AWS Config is used to assess, audit, and evaluate the configuration of your AWS resources. It is implemented in many applications that use AWS to deploy. It helps in assessment, operational auditing and general governance of AWS resources.
I do not know or have used any other product in AWS cloud space that matches what AWS Config provides. We have some custom built monitoring and governance, however that is there because AWS Config does not provide it currently.
If you have multiple resources in your AWS environment then AWS Config can provide you with audit, governance, and comparison of any changes to your resource configuration over time. You can create alerts to be notified via AWS SNS if any configuration changes, which is very useful for development teams. Governance in an organization, like “Who made the change?”, “From what IP address?” is a very useful audit and operational governance tool.