Azure Cost Management + Billing provides detailed insights into organizational spending on cloud services and allows for managing and optimizing Azure costs. It helps in analyzing costs, creating budgets, and setting up alerts to stay within budget. This is critical for organizations to prevent cost overruns and to maintain financial control over their Azure resources. Azure Subscription does not offer these cost management insights and only provides a way to organize resources. Azure Monitor focuses on the performance and health of your applications, infrastructure, and network, but does not provide in-depth cost analysis. Azure Price Protection is a fictitious service that does not exist in Azure's offerings.