The ArcGIS Well-Architected Framework is a collection of concepts, patterns, and best practices to help organizations design, build, and operate ArcGIS systems. The ArcGIS Architecture Center is the website that makes the ArcGIS Well-Architected Framework available, along with other design and implementation related resources in the Architecture Library.
Take a quick tour in the short (~4min) video below, or continue learning about the mission and intended audience.