What is the difference between a software high-speed counter and a hardware high-speed counter?

The DVP series PLCs have both software high-speed counters and hardware high-speed counters. All software counters have limited total bandwidth for input and can be short of total bandwidth and pulses for the counting due to too many high-speed counters or enabled external interruptions. However, the hardware counter does independent counting following the hardware input specifications and will not be affected by its other high-speed functions or the total bandwidth problem.