Edge delivery refers to the process of delivering content from servers that are located close to the end-user's geographic location. This is typically achieved through a content delivery network (CDN), which places servers (referred to as edge servers or edge nodes) in multiple locations worldwide.
Architecture
There has been an evolution in the architecture from Helix 1, Helix 2, Helix/Franklin 3, Franklin 4, and Helix 5(work in progress).
This video series explains Adobe/AEM Franklin (Edge Delivery Services) concepts, which includes-