Functional foods look like food and are modified for greater nutritional value. Dietary supplements look like drugs and are made from food, isolated nutrients or food-like substances to augment health. Nutraceuticals are a sector of dietary supplements made only from whole foods to augment health.

Examples of nutraceuticals are natural foods, including antioxidants, dietary supplements, fortified dairy products, and citrus fruits, and vitamins, minerals, herbals, milk, and cereals. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/nutraceutical

Functional foods are generally separated into two categories: conventional and modified (2). Conventional foods are natural, whole-food ingredients that are rich in important nutrients like vitamins, minerals, antioxidants, and heart-healthy fats. https://www.healthline.com/nutrition/functional-foods

Functional food work as metabolically apart from their nutritive enrichment, while nutraceutical is derivatives of food that aimed to provide medicinal benefit along with nutrional aspect.

A functional food is a food claimed to have an additional function by adding new ingredients or more of existing ingredients. The term may also apply to traits purposely bred into existing edible plants, such as purple or gold potatoes having enriched anthocyanin or carotenoid contents, respectively.

A nutraceutical or 'bioceutical' is a pharmaceutical alternative which claims physiological benefits. In the US, "nutraceuticals" are largely unregulated, as they exist in the same category as dietary supplements and food additives by the FDA, under the authority of the Federal Food, Drug, and Cosmetic Act

https://en.m.wikipedia.org/wiki/Nutraceutical

https://en.m.wikipedia.org/wiki/Functional_food

Functional foods are food products that resemble traditional foods but possess demonstrated physiological benefits. However, nutraceuticals are commodities derived from foods, but are used in the medicinal form of pills, capsules, potions and liquids and again render demonstrated physiological benefits.

https://www.sciencedirect.com/science/article/pii/S092422440800229X

Nutraceutical a group of dietary components, which may be nutritional nonessential, have beneficial effects toward both health promotion

and disease prevention.

Functional foods: foods that provide benefits above and beyond traditional nutrition. A functional foods should have its good sensory characteristics.

Functional Foods are Food products that are part of the usual diet, but has beneficial effects that go beyond the traditional nutritional effects.

Nutraceuticals is a broad umbrella term that is used to describe any product derived from food sources with extra health benefits in addition to the basic nutritional value found in foods. Nutrient and non-nutrient compounds in food that have health promoting, disease prevention or medicinal properties are called Nutraceuticals.

Functional foods are foods that contain bioactive compounds naturally. Significantly, these foods can provide health benefits beyond the traditional nutritional value of the food. Here, the traditional nutrients refer to the regular vitamins and minerals found in that particular food. Generally, traditional nutrients are essential to the diet, and their deficiency causes classical nutrient deficiency diseases. That means; the functional foods contain a unique form of nutrient, which in turn promote the health . Neutraceuticals are the bioactive compounds found in fortified food, dietary supplements, and herbal products. However, they are often defined synonymously with functional foods due to the presence of a specific nutrient in a particular food. Some examples of nutraceuticals in fortified food are the calcium fortified in orange juice and vitamin D fortified in milk

For more details on what prof. C. A. Kalpana said, I have attached a European report.

The main difference between functional foods and nutraceuticals is that functional foods are food with bioactive compounds such as beta-carotene, lycopene, resveratrol, ferulic acid, etc. whereas nutraceuticals are the bioactive compounds found in fortified food, dietary supplements, or herbal products.

https://pediaa.com/what-is-the-difference-between-functional-foods-and-nutraceuticals/

Also, kindly check the following RG link that includes useful information about this debate:

https://www.researchgate.net/post/What-could-be-the-major-difference-between-functional-foods-and-nutraceuticals

Nutrition is functional food with bioactive compounds while nutraceuticals are bio active compound only without functional food.