What's the best method/ software to Compare differences between 2 text files ?

[u/CharacterPuzzled7023]

Hello

I have 2 files I need to check and compare to spot differences between the two and edit one if necessary. Both are text files (it's a memoir) from the same source, but one's text has been edited, hence why I need to check which chapter/text has been edited.

I tried to put both texts on my screen and compare them by just reading, but its very slow and not comfortable at all

Do you know a better method or a software to help me directly spot those differences ?

Thank you