# Basic document structure
\documentclass[a4paper,12pt]{article}
\begin{document}
A sentence of text.
\end{document}

# Document comments
% this text is a comment because the line begins with a %

# Comment blocks
\usepackage{comment}
\begin{comment}
This is a larger block of commented text
that can span multiple lines and is ignored
by the compiler.
\end{comment}