A Bit on LaTeX
LaTeX is a high-quality typesetting system, with features designed for the production of technical and scientific documentation. LaTeX is a markup language including a powerful macro language, and has established as the de facto standard for the communication and publication of scientific documents. Further information can be found at https://www.latex-project.org, a (not so) short introduction https://ctan.org/tex-archive/info/lshort/.
LaTeX sources are kept in files with the extension
which then can be converted to Postscript or PDF by means of
BibTeX is a regular companion to LaTeX that provides support for managing
bibliographic databases and including proper citations in LaTeX documents.
BibTeX "databases" are kept in plain text files with the extension
In case BibTeX is used, the latex and bibtex commands have to be invoked alternately:
(Observe that we can safely omit filename extensions, in which case the tools will assume the appropriate one.)