digitizer vs digitiser

digitizer and digitiser both are nouns.

Word	Noun	Adjective	Verb	Adverb
digitizer	Yes	No	No	No
digitiser	Yes	No	No	No

As nouns, digitizer and digitiser are synonyms defined as:

digitizer and digitiser: device for converting analogue signals into digital signals

Other synonyms of digitizer include analog-digital converter, analog-to-digital converter.

digitizer (noun)	digitiser (noun)
device for converting analogue signals into digital signals	device for converting analogue signals into digital signals