A sealant is like a special glue that we put on things to keep them closed or sealed shut. Think of it like a band-aid for objects. It helps to keep air, water or dirt from getting inside.
For example, imagine you have a piece of wood that has cracks in it. If you put a sealant on it, it will fill the cracks and keep water from getting inside the wood. This is helpful because water can make the wood weaker and cause it to break apart over time.
Sealants can be different colors and can be used for many different things. For example, some people use them to seal up their bathtubs so water doesn't leak out onto the floor. Others use them to seal up windows and doors to keep out drafts of air.
Overall, sealants are like magic glue that helps us keep things together and protect them from outside elements.