revalidateIfStale is not clear in doucmentation? What does it mean? What does it mean if data is stale?

[roker15]

revalidateIfStale is not clear in doucmentation? What does it mean? What does it mean by data is stale? If there is cache already there , is it stale or not? another thing what if revalidateOnMount contradicts revalidateIfStale. Is is possible to fetch data when tab is opened first time and then it stops fetching until i close the tab and reopens?

[MonstraG]

See #1400