Are the really old virus definitions updates purged out and deleted?

So I have Norton 360 on both my windows 7 and 10 computers. My question is with all the frequent updates the program gets over the weeks, months, and years, does it build up to a really large size of files, or are the really old virus definitions and other malware updates purged out and deleted after a long period of time so the files do not grow too large and take up valuable drive storage space. Okay thanks, Jim