Generally speaking, when texts are saved in word processors, the fonts used are not saved as part of the file. If an unusual font has been used and is not available on other computers where the document is viewed, it will be substituted, with rather unpredictable results.
Most modern word processors use Unicode (UTF-8) encoding by default. This is a great improvement on previous systems because with Unicode many alphabets are available with the same encoding system. Now, with UTF-8, gone are the days when Cyrillic characters will not show up correctly in a document that for the most part uses the Roman alphabet, to take just one example.
Some programs still use old encoding systems by default. If you are importing text from one of these programs, you will typically be shown a file conversion dialogue box. Always convert to UTF-8 if given the opportunity.