Excerpt from this article:
(Another aside, about terminology: some people say screengrab or screen capture or screencap. I find the first one unpalatable [literally] because of the quick succession of “cr” and “gr” sounds you have to make with the hard palate, and the second two a little too focused on the feeling of a “gotcha” but I can see how both of these options might appeal to people who don’t want to deal with the complications of declension involved with “to shoot.”)
The screenshot has totally revolutionized the world. (This is an opinion and an argument, and you could insert many different nouns in that sentence and defend them admirably, but this is the hill I have chosen to command-shift-4 on.) How else would minor celebrities share their public statements to social media, but with screenshots of an apology composed in their skeuomorphic Notes app? How else would we preserve offensive, objectionable, and otherwise deleted tweets for posterity to tsk-tsk over on the evening news? How else would we share with our IT representative the error message we keep receiving when we try to export the file to PDF?