Hunk means a piece of change in the Git world. Stage hunk means it is being added to the staging area.
Discard Hunk means remove the change without trace.
Replace the word ‘hunk’ with ‘change’ and it becomes pleasurable to follow Git.
If you don’t want to commit your change , you will have to discard your changes (hunks). God knows why the Git geeks chose “hunk” but it is what it is. Learn to love it and other idiosyncrasies(stash,rebase, to survive in Gitland.