Lag

Lag refers to a delay between an action or input and its observable result. It can arise from the time required to process information, transmit data, and render a response.

In computer networks, lag is commonly called latency and is often described as the time for a data packet to travel from source to destination and back (round-trip time). Causes include propagation delay, serialization, queuing, switching, and processing at endpoints. Jitter describes variation in latency.

In interactive media such as video games, lag may refer to input lag (delay between a user action and its in-game effect) and display lag (time to render and present a frame). Network lag adds to the overall delay.

Streaming video or audio can experience lag in the form of buffering, where playback is intentionally paused to accumulate data.

Lag is typically measured in milliseconds (ms) or frames, and high lag reduces responsiveness and can cause desynchronization in audio-visual content.

Common causes include limited bandwidth, network congestion, routing inefficiencies, hardware bottlenecks, software inefficiencies, and display refresh rates. Mitigation includes improving connectivity, upgrading hardware, reducing processing steps, optimizing software, and tuning settings such as frame rate, buffering, and quality.