Calories (nutritional)
A nutritional calorie, specifically a kilocalorie (kcal), is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius. In nutritional contexts, the term "calorie" typically refers to a kilocalorie.
Joules
The joule (J) is the SI unit of energy, named after the English physicist James Prescott Joule. It is the work done when a force of one newton moves an object by one meter in the direction of the force, so it is sometimes known as a newton-meter. It is also one watt-second.