Exposed film and print papers are developed in chemical baths in the darkroom. Machines in the darkroom called enlargers are used to blow up or reduce the size
(scaling) of photos for printing and to crop them for printing.
Optical filters can be used with the Enlargers to modify the appearance of photographs. Darkroom tricks can be used to superimpose part or all of one photo upon another for printing. Text or artwork can be superimposed upon a photograph too.
As sufficient computer resources were developed and deployed to enable digital image manipulation and editing, software was developed to do just that. Thus, today everything from snapping photos digitally, to editing photos, to printing photos can be done digitally -- digital cameras for snapping the photographs, digital computers and software for editing the photos, and digital (computer) printers for making photo prints.