Why did the battle of saratoga mark a turning point in the war?

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.