A simple example of digitization can be the transition from analog cassette tapes to digital compact discs. Cassettes hold data in reels of magnetized tape spooled together, while the data on CDs are etched using lasers in the binary form of pits (0) and flats (1). Digital data is more indexable, referenceable, replicable, accessible, and manageable. That is also the reason we can repeatedly access favorite tracks separately without having to buzz back and forth, winding, and unwinding the magnetic spool of a cassette tape.
In the manufacturing world, converting a unit of data such as a measurement from a manual or mechanical reading to electronic format is considered digitization.