Which AWS service or tool provides this functionality?

Explanations:

AWS Organizations is primarily used for managing multiple AWS accounts under a single organization and does not provide cost forecasting capabilities.

AWS Budgets allows users to set custom cost and usage budgets, but it does not provide detailed forecasting capabilities for costs in a quarterly format.

AWS Cost Explorer enables users to visualize, understand, and manage AWS costs and usage over time. It provides forecasting tools to estimate future costs based on historical data.

AWS Cost and Usage Report provides detailed information about costs and usage but does not offer forecasting functionality. It is mainly used for detailed billing analysis.