What is a voltage transient?

Also known as transient voltage transient pulse, it is noted within a certain time interval a between two consecutive steady-state phenomenon in a very short period of time or number of changes that occur.

This momentary pulse may be any pulse of one polarity in one direction, and may be the first peak of the oscillation attenuation of either polarity, i.e., the first peak occurs at either polarity of the damped oscillation.