Essential oils are concentrated oils that are derived from plants. Several types of oils are produced from citrus species, including oranges, lemon, and grapefruit. Orange essential oil is extracted from the rind of the sweet orange, Citrus sinensis. This is done by a method called cold pressing, which uses pressure to squeeze the oils from the rind. Sometimes, the leaves and flowers from the orange plant can be used as well. Orange Essential Oil, most commonly referred to as Sweet Orange Essential Oil, is derived from the fruits of the Citrus sinensis botanical. Conversely, Bitter Orange Essential Oil is derived from the fruits of the Citrus aurantium botanical.