when a filter is applied to a view, what data is affected?

When a filter is applied to a view, the data affected is specifically the data from after the filter was created. In other words, the filter affects only the data that comes in or exists after the filter's creation, not data before the filter was created. The filter limits the data displayed in the view but does not alter the underlying data itself. It essentially reduces the amount of data shown based on the filter conditions but leaves the original data intact.