Essential oils are highly concentrated plant extracts that have been used for centuries for their therapeutic and aromatic properties. They are typically extracted through distillation or cold-pressing, and can be used in a variety of ways, including aromatherapy, topical application, and ingestion. Essential oils are categorized based on the plant source, with popular categories including citrus, floral, herbaceous, woody, and spicy. Each category has its own unique properties and benefits, making essential oils a versatile and popular choice for natural health and wellness.