A pop-up book is a special kind of book that has pictures that pop up and come out at you when you open the pages. Imagine a regular book that you read with your eyes - you turn the pages and see pictures and words that tell a story. Now imagine that some of the pictures in the book are made to pop off the page when you open it, like a surprise!
The way it works is that the pictures are usually made from paper and are very carefully folded and glued together so that when you open the page, they "pop" up into 3D shapes. Sometimes the pop-ups are simple, like a tree that pops up from the book, or a house with all its doors and windows that you can open up. Other times, the pop-ups are more complex, like a whole landscape or cityscape that comes to life in front of you.
Pop-up books are really cool because they make reading and storytelling more interactive and fun. Plus, the 3D aspect can help you imagine the story even more vividly in your head. However, because pop-up books are so delicate and precise, you have to be careful when you read them and make sure you don't accidentally rip or damage the pop-ups. Overall, pop-up books are a neat way to bring a story to life and make reading an adventure!