Round Trip Time is a critical performance measure in network latency, involving the duration from when a data packet is sent from the sender to when it is acknowledged by the receiver. This metric helps in assessing the responsiveness of a network connection and the efficacy of real-time communication systems. RTT is influenced by several factors, including propagation delay, transmission delay, queuing delay, and processing delay, which together dictate the speed of data transfer in web applications, online gaming, video conferencing, and other interactive services.