I was asked recently whether “digitization” or “digitalization” is correct. It strikes me that “digitalization” is growing, but that’s just anectdotal. “Digitization” remains more common in a Google search, and it is more logical than “digitalization.” Digitize to convert to digits (as in binary). Digital is an adjective.
The words have long histories dating to before the digital age. “Digitize” once meant to point or to manipulate with the fingers. The first use to mean converting analog signal to digital dates to 1953 in the Oxford English Dictionary corpus. Digitizing data first appears in 1973 (at least in OED’s files).
According to Bryan A. Garner in “Garner’s Modern American Usage,” “digitalization” also has a specialized medical use: the administration of digitalis, a heart medicine prepared from the digitalis (or foxglove) plant. The digitalis plant was named in 1542 because of its shape like a thimble, or “fingerhut” in German.
Digit, the Latin word for our fingers and toes, came to mean numbers, especially numbers less than 10, because we count them on our digits.
And here is one more just for fun: a digitorium is a small, quiet keyboard used to exercise the fingers for piano playing.