What NTP metric indicates how close a server is to the authoritative time source?

Stratum is a key NTP metric that defines the "distance" of a time server from a primary reference clock. Stratum 0 devices are highly accurate reference clocks (e.g., atomic clocks, GPS receivers). Stratum 1 servers are directly synchronized to a Stratum 0 device. Stratum 2 servers synchronize to Stratum 1 servers, and so on. A lower stratum number indicates a server is closer to the authoritative time source and generally more accurate. Time zone defines a geographical region with a uniform standard time. Latency measures the delay in network communication, not the server's proximity to the authoritative time source. Hop count indicates the number of routers a packet traverses, which is a network path metric, not an NTP accuracy metric.