In the signal processing concept is frequently translated total sample and hold circuit, sampling and holding circuit. It allows us to sample a varying input voltage at any point in time (sample) and frozen on a signal quasi (hold) to evaluate them further. Example, one can digitize a relatively slow speed AD converters and analog signals. Also in synthesizers, such sample-hold circuits used
Here are a few links to S & H schematics

Here you may find Circuit, Basics, Schematic Diagram and DIY Kit components for Sample and Hold