The main differences between fragrance oils and spray perfumes for a better understanding of fragrance oils:
Oils are generally much stronger, as they are the purest form of perfume.
Spray oils are usually diluted with alcohol at various levels of concentration. Oils can last up to 24 hours, while sprays can last from 2 to 8 hours, depending on the level of fragrance oil present in them.
Fragrance oils do not dissolve easily from your skin. They are activated by the heat of your skin and radiate outward as your skin heats up. This is why they are applied at the pulse point; the warmer the skin, the more you smell the fragrance. Fragrance oils don't start off strong because they rely on the heat of your skin and take time to activate.
Perfume sprays, on the other hand, start strong as they mix with the air and evaporate within a few hours. When perfume spray combines with oxygen in the air, it dissolves due to the nature of alcohol.
Therefore essence fragrance oils in roll on last longer and are more intense but mostly for you and those who will be very close to you. While spray on fragrances diffuse into the air and therefore evaporate more easily, but make your presence felt everywhere!