Jitter refers to the inconsistency in the time it takes for data packets to travel across a network and reach their destination. When you send information over a network, it is broken down into smaller units called packets.

Ideally, these packets should arrive at their destination in a steady, predictable manner. However, due to various factors like network congestion or routing changes, the time it takes for each packet to arrive can vary. This variation in delay is known as jitter.

High levels of jitter can lead to problems such as poor audio or video quality during calls or streaming, as the data does not arrive smoothly and consistently.