Calories?!?

What exactly are calories? Are they what make up fat, and everytime we eat something the calories add up to make us fat? What if I dont eat something for a whole day, and I jog for like 3 hours..Will I end up with a huge improvement?
(No "Just google it" answers please.)

Calories don't make up fat, but fat has calories! Calories is sort of like a number expressing how much energy the food we eat will give us. If you don't eat for a while day and jog for 3 hours...let me tell you! You will be very sore and hungry and would probably pass out. Also, because you would have stopped eating, your metabolism, or the rate at which you burn calories, will slow down also. This can lead to weight gain. Just be careful of what you put into your mouth and then you should be fine.

I know people are gonna get all technical, on how a calorie is a measurement of energy, specifically the amount of energy required to raise the temperature of one gram of water by a degree celcius...

but i now the answer you want is:

calories are your energy, they do not make up fat, they simply indicate how much energy you have spend on burning fat, and in order to lose them you gotta have them through food, so DO NOT STOP EATING it will not help you, In fact eat more often, but small amounts and less junk food, drink lots of water, before, during and after exercise.

do not avoid calories in food, avoid trans fats, and carbs...

An adult male needs about 1,500 calories per day for body maintenance. Eat this number of calories in fruits, veggies, whole grains, high protien foods and high fiber foods. Enjoy your food; make friends with food; trust food! Calories are determined by the amount of heat produced when a food is burned (!), and calorie is from Latin for heat/hot. However, the calorie count of some foods is neutralized by the fact that they can't be digested, and can't release their heat. Insoluable fiber doesn't break down in the body, so whatever number of calories it may have can't be counted. Teach youself about foods, metabolism, digestion and energy. In time, you'll arrive at a poised state of eating without counting, weighing and measuring everything before you eat it.