Alright, kiddo! Collodion is a special liquid that people use to make pictures. When you take a regular picture with a camera, the image is saved on a camera card or computer. But with collodion, the picture is saved on a sheet of glass or metal instead!
First, the person takes the glass or metal sheet and pours collodion liquid on it. Then they put the sheet in a container with a special chemical called "silver nitrate" for a few minutes. After that, the sheet is put into a camera and the picture is taken.
Once the picture is taken, the person quickly takes the sheet out of the camera and puts it in another container with another chemical called "developer". This makes the picture appear on the sheet like magic!
Finally, the person rinses the sheet with water to remove the chemicals and makes sure the picture is saved on the sheet forever. And that's how collodion makes pictures!