Have you ever played with Play-Doh? You can use it to make different shapes like a ball, a snake, or a flower. These shapes are called concrete things because they are things you can touch and see.
But have you ever thought about shapes that you can't touch or see? These are called abstract things. Abstract things are ideas, concepts, or qualities that are not physical objects, like love, time, or bravery. You can't touch or see love, but you can feel it.
So, concrete things are real and physical, and you can touch and see them. Abstract things are ideas and qualities that you can't touch or see, but you know they exist.