The BibTeX program was written primarily to deal with references in English. It is very limited in handling accented characters, and even more limited with non-Latin letters. In contrast, the Biber program was written from the start to handle a mix of scripts properly.
This means that if you are sorting your bibliography, and you need to sort in
anything other than English order, you really should be using biblatex and
Biber, rather than natbib and BibTeX.
If you load the hyperref package (as covered earlier), it will
automatically make some content in your bibliography into links. This is
particularly useful for URLs and DOIs.
While the overall syntax of the BibTeX files is the same whether you use the
BibTeX workflow or biblatex, the set of fields that is supported (used by the
style) and their exact meaning may not only vary between the BibTeX workflow
and biblatex, but also between different BibTeX styles. A large ‘core set’ of
entry types and fields is the same for almost all styles, but there are
differences in some fields.
A common example is the URL. Some older BibTeX .bst styles (most notably
the ‘standard BibTeX styles’, e.g. plain.bst, unsrt.bst, …) predate
the invention of the URL and have no dedicated field for the URL of an online
resource. Many newer styles do have a dedicated url field. The workaround
to show the URL in the older styles is usually to use the howpublished field,
but with the newer styles it is of course preferable to use the dedicated
url field.
In order to be able to make use of the full potential of your used style you will have to find out the set of fields it supports and their semantic.