The difference between plaque and tarter is that the tarter starts out as plaque and then turns into tarter.
So in a way plaque and tarter are almost the same thing.
The plaque on your teeth is a sticky, colorless film that constantly forms on your teeth and when that plaque is not removed by brushing your teeth often enough then it leads to tarter which cannot be easily removed by home remedies.
Simple tooth brushing will also not remove tarter from your teeth.
When your plaque turns into tarter then you need a dentist to remove the tarter on your teeth.
Nothing else will remove the tarter.
Tarter is also known as Calculus which cannot be removed with a toothbrush and only a dental professional can remove the tarter or Calculus during an oral cleaning.