“Macros” is short for macronutrients. When we talk about nutrition you will hear us use refer to counting your macros (macronutrients). These are the main staples of our nutrition and our main sources for energy, also what you would know as your protein, carbs and fats.
Each macronutrient is metabolized and utilized differently from each other. Protein and Carbs have 4 calories per gram while fat is 9 calories per gram. For an fyi alcohol is 7 calories per gram while it isn’t a big source of energy for us many like to enjoy some sort of alcoholic beverage occasionally. So, when someone says all calories are not the same this is what they are referring too, that not all macronutrients are the same.
This is a very simple explanation of what can be a very complex topic!