Understanding sample rate

Sampling rate is essential for the selection of the proper test and measuring equipment. Two methods of sampling are used in various digital storage oscilloscopes (DSO), namely equivalent-time sampling and real-time sampling. The choice of the test instrument will depend on whether measurements are on repetitive signals, for which equivalent-time DSO's are suited, or the focus is on single-shot phenomena, for which DSOs with real-time capture and a high sample rate are the proper choice.
What is sampling rate and why is it important in the selection of test and measuring equipment? What is sampling rate? Furthermore, why is it important? The answers to these [...]