Photomontage or Collage
In simple terms, this is multiple images presented as one image.
Collage made from photographs, or parts of photographs, is called photomontage. Photomontage is the process (and result) of making a composite photograph by cutting and joining a number of other photographs. The composite picture was sometimes photographed so that the final image is converted back into a seamless photographic print. The same method is accomplished today using image-editing software. The technique is referred to by professionals as compositing.
This differs in the collage art form, where the pictures are cut or torn to fit the space and are irregular. A collage tends to be an artful, illogical, arrangement. The pictures in it are about art, texture, arrangement or pattern. The individual parts have no particular value in their own right.
For inspiration:
https://www.anothermag.com/art-photography/3318/top-10-collage-artists-hannah-hoch-to-man-ray