The term "dextrorotatory" refers to a property of certain molecules that rotate plane-polarized light to the right, or clockwise. This characteristic is often observed in chiral compounds, which are molecules that have non-superimposable mirror images. Dextrorotatory substances are typically labeled with a "+" sign, indicating their ability to rotate light in this direction. In contrast, "levorotatory" compounds rotate light to the left, or counterclockwise, and are denoted with a "−" sign. The distinction between dextrorotatory and levorotatory is crucial in fields like chemistry and pharmacology, as the two forms can have different biological effects despite having the same molecular formula.