AWS Cost Explorer is the AWS service or tool that helps users visualize, understand, and manage spending and usage over time. AWS Cost Explorer is a web-based interface that allows users to access interactive graphs and tables that display their AWS costs and usage data. Users can create custom reports that analyze cost and usage data by various dimensions, such as service, region, account, tag, and more. Users can also view historical data for up to the last 12 months, forecast future costs for up to the next 12 months, and get recommendations for cost optimization. AWS Cost Explorer also provides preconfigured views that show common cost and usage scenarios, such as monthly spend by service, daily spend by linked account, and Reserved Instance utilization. Users can use AWS Cost Explorer to monitor their AWS spending and usage trends, identify cost drivers and anomalies, and optimize their resource allocation and budget planning. References: Cloud Cost Analysis - AWS Cost Explorer - AWS, Analyzing your costs with AWS Cost Explorer