Performance counters are organized by groups of system resources. Examples of performance counter groups are memory, CPU, and disk. The counter groups and specific counters used on any vSphere server depend on the server configuration. The

vSphere API Reference

contains a table for each counter group. The table includes the counter name, type of statistics being collected, unit of measurement, level, and so on. The

vSphere API Reference

page for the

PerformanceManager

managed object contains links to the tables.