I'm by no means a specialist or technician, but I think it's correct to say that adapting to unicode means that you change the language you type in rather than the font. That way, regardless of which font you use, the letters should still show up in the correct language.
If you type an aleph in Hebrew, it will be an aleph whether you use Times, Arial or Segoe.
In the olden days, rather than changing your typing language, you would change the font to Yehudit or another Hebrew font. But if you changed the font to Times, it would show up perhaps as an a or an x or something else - each font would map the letters differently.
I have that issue looking back at old seminary papers, where the English is written in Arial but the Greek was in Helena. Without Helena installed it looks like gibberish.
Some fonts don't support other languages, so if you have unicode, your word processor will default to whichever font best supports that language (usually Times New Roman), but will leave the rest in your chosen font.
Long story short: if you can, change the language not the font, and this will make your work transferrable and future proof in a way that changing font did not permit.