# LaTeX
**Latex** (stylized as $\LaTeX$) is a markup language used to create scientific papers. It's the language used to produce PDF documents, like the ones you'll commonly see on [arXiv](https://arxiv.org/).

Latex has a simple declarative syntax that looks like `\command[opt1][opt2]...[optN]{arg1}{arg2}...{argN}`. That is to say, most commands start with a backslash `\`, followed by command name + arguments given in square or curly braces. For example, `\textbf{Hello}` makes a bold text **Hello** while `\textit{World}` makes an italic text *World*. "Bf" stands for "bold font" while "it" stands for "italic". Arguments in curly braces `{ ... }` are mandatory, while arguments in square brackets `[ ... ]` are optional.

Latex documents have the extension `.tex`. Unlike HTML -- which you can view in any browser you can't readily view latex documents until you compile them with a latex compiler. The most common compiler is `pdflatex`. This compiler turns `.tex` documents into `.pdf` documents. PDFs can then be viewed by a PDF viewer or in the browser.

The following is a minimal latex document.
```latex
% Compile: pdflatex main.tex
% Result:  main.pdf

\documentclass{article}
\begin{document}
Hello world!
\end{document}
```
You can now open `main.pdf` and see the result!