What does NG stand for/mean? What is the difference between categories?

NG means New Game, which of course means that you start with an empty profile with no items and 4 hearts. NG+ means New Game+, meaning that you can use a profile that has already been played on before and can use any item except potions. The “True” on the categories mean that you can use any glitch such as spamming e to skip a floor.