Sampling is the acquisition of a continuous-time analog signal at specific time intervals.
For this purpose, the analog signal is sampled at the sampling times t1, t2, etc. and the voltage value obtained is fed to a hold circuit. Sampling is usually performed together with voltage holding in a sample and hold circuit. The time interval between the individual samples is the sampling rate.
The values sampled at a certain time represent the values to be digitized for the AD converter, which are digitized in the AD converter by means of quantization.