The Azure Well-Architected Framework is a set of best practices and guidelines for designing and building cloud-based solutions on Microsoft Azure. It covers five key pillars: operational excellence, security, performance efficiency, reliability and cost optimization. The framework is intended to help organizations optimize their solutions for the unique characteristics of the cloud, such as scalability and resiliency. It includes a set of tools and resources, such as the Azure Well-Architected Review, to help organizations assess and improve their solutions. The framework is regularly updated to reflect Azure's latest best practices and changes.