Carrier oils are vegetable-based oils that are used as a base for essential oils, which can be diluted in them before being applied to the skin. They help to reduce any potential irritation or sensitivity that may occur from using pure essential oils directly on the skin. Carrier oils also have their own therapeutic properties and can be used alone as a moisturizing treatment for dry or damaged skin. Some common carrier oils include jojoba oil, sweet almond oil, avocado oil, and grapeseed oil.