Okay kiddo, so I'm going to tell you something called "from each according to his ability, to each according to his needs". It means that in a society, everyone should contribute whatever they can, depending on their skills or abilities, and in return, they should get what they need to live a good life.
Do you remember how we discussed sharing toys? In the same way, if we share our resources, we can help each other. Imagine you have lots of food and your friend has none. If you share your food with your friend and he shares his toys with you, then you both get what you need to have fun, and no one goes hungry. Just like that, in a community, everyone works together to make sure everyone has what they need.
When we all contribute what we can and share with each other, then everyone can have a good life. This way, no one is left alone, and everyone is taken care of in a fair and loving way. Isn't that nice?