This is Kate's jacket. = This jacket belongs to Kate.
That's our neighbors' dog. = That dog belongs to our neighbors.
Belong with means that things/people are similar and should be together. If one person in a romantic relationship says "You belong with me," it is like saying that it is destiny for the two people to be together.
You can also use belong with or belong in for putting an object into a category with other, similar objects:
That book about humans traveling to Mars doesn't belong in the history section. It belongs with the other science fiction books.
An object belongs IN a category, and belongs WITH other similar things.
Additional amounts of calcium, phosphorus and iron are required by bones to increase their endurance. Being rich in calcium, iron and phosphorus, sapota fruit greatly helps in enhancing and strengthening the bones. Sapota helps in strengthening the intestines and in improving their performance. In short, eating sapota or chikoo fruit helps in developing body resistance against many infectious diseases.