As for applications. Well, just about any document (research paper, book, article, letter etc.) which needs to be presented professionally can be done with LaTeX.

On this board, include your Latex formulas between [ math ] and [ /math ] (without the spaces. I added the spaces so the code would show up. Other boards may use dollar signs or [ tex ] [ /tex ].

We use [noparse]\(\displaystyle ...\) or \$\$...\$\$[/noparse] and \$...\$ for inline code. The first two sets of tags generate full $\LaTeX$ on a new line. Try it out!