You ask about "cropping". Cropping is the cutting-off of one or more sides of a photograph, either when printing it, or preparing to email it. That is, you crop-out or crop-off (or cut-out or cut-off) the less interesting parts to highlight what is interesting, so as the viewer's attention is not distracted by unimportant detail and the eye is drawn to what is important in the original photo. This is also achieved by "blowing up" a section of the photo's negative.