The term "latency" measures the delay experienced in a network and is typically expressed in milliseconds (ms). It indicates the time taken for data to travel from the source to its destination, impacting the responsiveness of applications and services. High latency can lead to delays in communication, negatively affecting user experience, especially in real-time applications like online gaming, video conferencing, and VoIP calls. Factors influencing latency include network congestion, distance between devices, and the quality of network infrastructure.