The advanced going in the Daily table is the going reported by the course the day before the race.
The going in the Historic table is the actual going the race was run on.
These two going descriptions can vary due to drying ground or rainfall on the day of the race.
Clearly the Historic data is the more accurate for past analysis, but if you want to use going information predictively to inform live betting decisions you have to use to Daily data as that all that's available for races yet to happen.