Jitter is an important performance metric to monitor in situations where real-time applications are being used, such as Voice over IP (VoIP). It measures the variability over time of the packet latency across a network. A consistent transmission delay is crucial for the quality of these applications. While bandwidth indicates the volume of data that can pass from one point to another in a given amount of time and is important for capacity planning, it does not address the consistency or delay variability of packet arrivals. Packet loss indicates data that never reaches its destination but does not inherently describe the delay characteristics. Latency measures the overall delay packets experience, but on its own does not specify variability.