Reference Material:

https://docs.aws.amazon.com/general/latest/gr/aws_tagging.html
Under Tagging AWS resources:
>> Tags for cost allocation :
AWS Cost Explorer and detailed billing reports let you break down AWS costs by tag. Typically, you use business tags such as cost center/business unit, customer, or project to associate AWS costs with traditional cost-allocation dimensions. But a cost allocation report can include any tag. This lets you associate costs with technical or security dimensions, such as specific applications, environments, or compliance programs. The following is an example of a partial cost allocation report.