I know a kilocalorie is 1000 calories, but I've been looking at a food lake for a cracker that says it has 45kcal, how would it be possible a cracker has 45000 calories?
It's complicated... If it says 'Calories', then that would be the same as kCal. The emphasis is on the capitalisation. There are 1, 000 calories in 1 Calorie or kCal.
No, they mean the same thing. Kilocalorie is the correct term but it has been shortended to calorie in most cases.