Jitter

Jitter is a general term used to describe phase fluctuations that occur during data transmission. To put it more precisely, it is a distortion of signal transmissions in optical and electrical signals.
These distortions usually occur during data transfers, screen outputs or when writing to or reading media.
These are changes in signal frequencies over time, for example in the case of a digital signal at the time of the transition from one signal amplitude to another.
The jitter is also measured with an eye diagram, among other things, and occurs primarily at high frequencies. This usually results in data loss or delays in writing and reading from storage media.
The most common causes of jitter include noise, crosstalk, and inaccuracies in laser scanning.