Here is the official definition from the The International Cosmetic Ingredient Dictionary and Handbook:

“Aroma is a term for ingredient labeling used to identify that a product contains a material or combination of materials normally added to a cosmetic to produce or to mask a particular flavor.”

INCI shows the only purpose of aroma to be "flavouring".

However, due to regulation differences, some companies may use aroma in place of parfum.

In Canada, this ingredient only has to be listed in concentrations above 1%.

This ingredient can be found in makeup, sun care, and skincare.

Limonene acts as an antioxidant, meaning it helps neutralize free radicals.

When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.

The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.