Simple definition
A NUMA node groups processors and nearby memory with relatively fast local access.
Purpose and use
A NUMA node groups processor and memory resources with a locality relationship in the exposed topology.
How does it work?
Access to another node’s memory can differ from local access.
Example and verification
Review task placement and memory allocation across nodes when investigating latency or imbalance.
Points to watch
A NUMA node does not always equal one physical socket; a platform can expose multiple domains per socket.
In short
Use the reported topology rather than inferring nodes from processor count alone.