Less calories or carbs?

What is more effective to eat Less calories or carbs? What is the difference? I’ve been told first to eat fewer calories and then I meet a friend who told me that carb are important. I am confused now. I’ll appreciate explanation. Thank you.

You don't know this but when you're a low carb diet, you actually eat fewer calories. As many people think that eating lots of meat, eggs, cheese, etc. means that you're ingesting a lot of calories, but that is incorrect. When on a low carb diet, all you have to do is watch your carb and protein intake and you don't have to count your calories.