Grams and kilograms are known to be units of measurement that are used when you want to know the weight of different things. Their main difference is for what items they would need to be used for measurement purposes. For example, grams are normally used when you want to measure objects that are very lightweight. If you want to measure a paperclip, you can be sure that using grams for measurement will be more accurate. Using kilograms, on the other hand, will be used when you want to measure bigger objects. This explains why when people are trying to purchase fruits, they would use kilograms instead of grams because fruits are normally heavier.
A gram is the type of unit that you will use when you would like to know the measurement of objects that are very light. For example, you would like to know the weight of a petal. You know that it is nearly impossible to measure this so you will use grams for it. Just one paperclip will be about a gram, but lighter objects will not even reach one gram. You will use kilograms when you would like to measure heavier objects. For example, a liter of water will weigh about a kilogram. The more liters of water that you need to measure, the heavier the kilograms are going to be. Kilograms will always be bigger than grams. You need 1000 grams in order to make 1 kilogram.