For example, I have one function called f. Now I make some change to f and create a new function called f'. But how do native people read the "f'"? Like "f apostrophe"?
Mathematician here. We pronounce f' as "f prime".
(Addendum: native English speaker in the United States. So, "we" refers to that group.)
From Wikipedia: "In mathematics, the prime is generally used to generate more variable names for things which are similar, without resorting to subscripts – x′ generally means something related to or derived from x."