Frontend & browser·The network from the browser
you looked at the timing bars and saw one request that could not start until three others had finished.
Network waterfall
Also calledwaterfall chart, request timeline
The network panel's view of every request as a bar positioned by start time and sized by duration. The shape carries the diagnosis: stair steps mean a dependency chain, a long pale segment before a bar means the request was queued or blocked, and a wide gap before anything starts means server time. It is the first place to look for a slow page and the last place most people look.