Okay, so there are two types of things in the world: organic and inorganic. Organic means something is made of living things or used to be alive, like plants and animals. Inorganic means something is not made from living things or was never alive.
An inorganic compound is a combination of two or more elements that do not have carbon atoms in them. Carbon is a very important element for living things, so if a compound does not have carbon in it, it is not organic.
So, for example, water is an inorganic compound. It is made of two elements: hydrogen and oxygen. There is no carbon in water, so it is not organic.
Other examples of inorganic compounds are sodium chloride (table salt), calcium carbonate (found in shells and rocks), and iron oxide (rust). These compounds are important for many things in the world, like making rocks and minerals or seasoning food.
In summary, an inorganic compound is something that is not made of living things and does not contain carbon in it.