In time/frequency counters/analyzers in technical specifications you can almost always find resolution and digits per second values next to each other. What is the difference?
Carmel Instruments products page for time interval analyzers / frequency counters explains it as follows:
Freq. Resolution - The resolution for Frequency Average and Period Average functions is dependent on the single-shot time resolution and the duration of the measurement (effective gate time). It is easier to specify it as a number of digits per second. For example, 12 digits/s means that you will get 12 digits of frequency resolution with a 1 second gate time, or 9 digits in 1 millisecond. If the signal input is 1 MHz, 9 digits of resolution translates to 0.001 Hz resolution.
So some of the comments were on the right track. I note that this specification gives no indication of accuracy and, as posted in the comments.
Back to your question:
What's the difference between measurement resolution and digits per second in time measurement devices?
According to Carmel there isn't a difference other than it is easier to relate meter resolution to time interval when using digits per second.