\documentclass[12pt]{article} %Specifies the type of document.
\title{A Example Document} %The title of the document.
\date{Sunday April 27} %The Date
\author{Your Name} %Your Name
\begin{document} %Start the Beginning of the document.
\maketitle
Hello World! %Content Goes Here
\[\frac{3x}{8y} \] %Fractions
\[ \lim_{x \to +\infty} \] %Limits
\[\sum_{i=1}^{3n}4i^2 \] %Summations
\[ \int_a^b f(x)\,dx \] %Integrals
\section{This is a major section!}
\subsection{This is a subsection!}
\subsubsection{This is a Sub Sub Section yes they do go deep.}
Additionally \LaTeX also offers two other section dividers
\paragraph{...}
\subparagraph{...}

\end{document} %Close the Document