A herbal oil is a maceration of a herb in a base, carrier or vegetable oil. A herb is steeped in oil which then yields its chemistry or active substances passing them into the oil. Classically such oils have been used since the dawn of time and ancient Greeks and Romans used them extensively for all sorts of conditions from sunburn to muscle ache.
Fragrant Earth provides a select choice of use for oils for everyday occurrences such as for minor bumps and bruises, aches and strains and so on. They are safe to use but are for external use only and should be massaged or applied to the skin. Any good herbal will give more specific direction as to their use. Herbals are available from Waterstones or Amazon etc.