Citronella oil is a natural essential oil extracted from the leaves and stems of Cymbopogon nardus and Cymbopogon winterianus, two types of grass. It is commonly known for its strong, lemon-like scent and is often used in candles, sprays, and lotions to repel insects, particularly mosquitoes. In addition to its insect-repelling properties, citronella oil has been used in aromatherapy for its potential calming effects. It may also have antifungal and antibacterial properties, making it a popular choice in natural cleaning products and personal care items.