Okay, imagine you have a big coloring book made out of special paper called "fresco." You color in the pages with special paints and then hang up the pages on the wall. The colors and design make a beautiful picture.
But after a while, the sun, rain, and dirt can make the picture look old and faded. Sometimes parts of the picture fall off the wall or get covered by dirt or paint.
Conservation and restoration of frescos is like fixing that coloring book picture. People who specialize in this work carefully clean the fresco so it looks bright and colorful again. They might use special chemicals and tools to clean the fresco without damaging it.
If parts of the picture have fallen off, they might use special glue or paint to fix it and make it look like it did before. They might even add new paint to make the fresco look like new again.
Overall, conservation and restoration is like giving the fresco a makeover to make it look beautiful and bright again for everyone to enjoy!