The term "latency" in web services refers to the time delay experienced when a data packet travels from the source to the destination and back. It is a crucial factor affecting the performance of applications, particularly in real-time communications such as gaming, streaming, and video conferencing. High latency can lead to significant delays, resulting in a poor user experience. Measuring latency involves assessing the round-trip time between requests and responses across networks; minimizing it is essential for enhancing responsiveness and ensuring efficient interactions in web-based services.