I would like to better understand what is different on SD-Access. Can anybody explain or provide any pointers?
SD-Access is the automated version of campus fabric. It uses LISP for control-plane and VxLAN for data-plane traffic. In traditional campus fabric you needed to do the configuration manually, but by using SD-Access you have a controller (Called DNA Center) that will take care of automating your overlay as long as you have layer 3 connectivity among your fabric devices.
For more informaiton regarding sd-access, please check "CTHCRS-1800 - Cisco SD-Access - Building the Fabric Demonstration" from ciscolive.com. We'll be adding content in supportforums.cisco.com but in the meantime, it will give you a good idea on what SD-Access is capable of doing.
This link is the best content as far Cisco gave publicly regarding DNA Center.
Hope this helps.
Please refer the below Url for more information.
SD-Access enables policy-based, automated network enforcement for access, security, application quality, and monitoring across all network domains.
SD-Access is the foundation of Cisco DNA.DNA-center plays as automation & orchestrate tool to build campus fabric network
You can refer this document: