A film splicer is like a special tool that glues parts of a movie together. Imagine you have a long strip of paper that has a picture on it (just like a movie). Sometimes this long strip of paper breaks into smaller pieces, but you still want to see the picture. A film splicer helps to put the broken pieces back together so you can keep watching the movie.
It's kind of like a puzzle where you have to match up the ends of the paper so the movie continues to flow smoothly. The film splicer has two arms that come together, almost like two hands holding onto the broken pieces of film. Then, it puts a special kind of tape on that holds the pieces together so they don't fall apart again.
Overall, a film splicer is a special tool that helps to mend broken pieces of film and keep movies playing uninterrupted.