# How to create simple comments in a margin next to the Document?

I've been digging through tons of SE-sites, package documentations for reledmac and parallel and many other pages, but I couldn't find the simple answer to this question. So, in hopes that it might help others, I will post the answer here.

What I'm trying to achieve is something like this:

Turns out that I simply oversaw the first search result linking to a Wikibooks page . But if it happened to me, it might happen to others as well.

The simple answer is the command \marginpar{} or, for a bit more control, the package marginnote. Their usage is described here.

The example in the question above was created with the following code:

\documentclass[a4paper,10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\usepackage{marginnote}

\begin{document}
Once upon a time, in the magical land of Equestria, there were two regal sisters who ruled together and created harmony for all the land.
\marginpar{Comment 1}
To do this, the eldest used her unicorn powers to raise the sun at dawn; the younger brought out the moon to begin the night. Thus, the two sisters maintained balance for their kingdom and their subjects, all the different types of ponies.
$$sin^2(x)+cos^2(x) = 1$$
\marginnote{Comment 2}[-0.75cm]
More text explaining the Formula, discussing the deep philosophy behind math, science and nature in general.
\begin{figure}[h]
\includegraphics[width=5cm]{example-image-a}
\end{figure}
\marginnote{Comment 3}[1cm]
And even more text. Did you know that 90\% of the Energy released in a thermonuclear supernova is being emitted via Neutrinos?

\end{document}