Which two elements define the two-tier leaf-spine data center architecture?

The two-tier leaf-spine data center architecture is characterized by its use of Leaf and Spine layers. The Leaf layer consists of access switches that connect to servers and endpoints. The Spine layer comprises high-speed backbone switches that interconnect all Leaf switches. This design provides high bandwidth, low latency, and predictable performance by ensuring that every Leaf switch is connected to every Spine switch, creating a non-blocking fabric. The options Distribution, Core, and Access are components of a traditional three-tier hierarchical network design, which is different from the leaf-spine architecture. In a three-tier model, the Access layer connects end devices, the Distribution layer aggregates traffic from Access switches and provides policy enforcement, and the Core layer provides high-speed packet forwarding between Distribution layers.