How much memory can a two-year-old child’s brain hold?

According to the University of Michigan Health Department, most two-year-old children are able to understand simple but crucial concepts like "now" or "later", also they begin to follow simple instructions like "come here", "eat your food", they begin to recognize objects and shapes "circle", "square", "triangle", as also they found easier to attach faces with specific calls like names or a sound.

All these information is saved inside children's brain if they find it important to live in their daily environment, because it's helpful information that they will need to use it later.