BibTeX is reference management software for formatting lists of references. It makes it easy to cite sources in a consistent manner. However, BibTex is typically used together with the LaTeX document preparation system.
On the other hand, Microsoft Word is still the most commonly used text editor and used in the group to share documents. Thus, I use BibTex to manage the bibliography and use MS Word to write documents.
One of the most famous reference manager software integrated in Word is EndNot, but unfortunately it is a very expensive and not open-source software. In Windows OS, there is a awesome plug-in called “Bib4Word”, but it is not usable in Max OS.