Dual photography is like taking two pictures at the same time, but from different angles. You can think of it like having two eyes - your right eye sees things from one angle, and your left eye sees things from a slightly different angle.
When you take a dual photograph, two cameras take pictures at the same time from slightly different angles. Then, a special computer program combines the two pictures to make one image that looks like it has 3D depth.
The cool thing about dual photography is that when you look at the picture, it feels like you can see how far away things are. Your brain thinks that the picture has depth, just like when you look at things in real life.
Dual photography is used in things like virtual reality and 3D movies, where you want to make the viewer feel like they are really there. So, it's kind of like magic - you can take a flat picture and make it look like it has depth!