@saurabh ,
The Azure Tenant Security Solution (AzTS) was created by the Core Services Engineering & Operations (CSEO) division at Microsoft, to help accelerate Microsoft IT's adoption of Azure. It is a logical progression of the DevOps Kit which helps them to move closer to the cloud security compliance solution implementation using native security capabilities in the Azure platform that are available today.
Last quarter, Azure Defender and Azure Security Center is renamed to Microsoft defender for the cloud. Microsoft Defender for Cloud (formerly known as Azure Security Center) is your tool for overall security posture management and threat protection. It’s going to give you recommendations on how to improve the secureness (or “hardening”) of your workloads running in Azure (e.g. PaaS services, networks, and data in Azure SQL) and visibility into other cloud environments (like AWS-specific security recommendations).
AzTS is a framework used on top of Azure security products (Microsoft defender for cloud, IoT, etc) with an objective to centralize all subscription scans, scale scanning capabilities, enable ASC policy-based news controls, etc. So, Using AzTS is like leveraging a proven framework for your company, but before you opt-in this framework please do a gap analysis if this solution will solve your company's security objectives.
Hope I clarified your question.
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Ravi Kanth