Performance Monitor (PerfMon) is an inbuilt Windows Tool for monitoring all aspects of Windows and hosted applications such as SQL Server. Performance Metrics in PerfMon are referred to as counters. PerfMon counters can be visualized in real time. A Data Collector Set is used to organize and schedule performance counter data as a single collection to be analyzed later. When you install SQL Server, windows adds counters relevant to SQL Server in Perf Mon.
Back in the day when budget was low and not many people were interested in SQL Server (at least in my environment), we had to develop