This is a very simple test of the most basic ability of HTML: marking up a text document so that it can be displayed sensibly on any terminal or in any screen "window" or "tab", no matter what its shape might be.  This was the main reason that HTML was invented, and the first browser's main job was placing the text in the available area so that it looked and read like ordinary text.  This paragraph was typed as one long line with more than 500 characters, but with no newlines to tell the renderer to start on a new line.  Here's the first newline in the file:
<P>
This text should be in a new paragraph.
This paragraph has a lot of short lines.
The only markup used is the &lt;P&gt; tag,
which marks the paragraph boundaries.
This tells the software to start a new line,
and to use one of the various paragraph indicators
to show that this text is in the second
paragraph.  Most browsers will default to using
a blank line to separate paragraphs, but some
will use the common publishing technique
of indenting the first line of a paragraph
by 3 or 4 spaces.
If you don't see three obvious paragraphs,
your software is failing its first job.
It has been told by the file's .html suffix that it's HTML,
and the server has passed on this information
in the header that it generates.
<P>
OK; I added a second  &lt;P&gt; tag, just for the fun of it.
You should be able to tell instantly that there are three
paragraphs in this text.
If you resize your screen or window,
or change the font size,
or rotate your pocket gadget,
you should see this text change in response so it still fits,
no matter what the shape of the available area might be.
In any case, this small file demonstrates what can be done in HTML
with only a &lt;P&gt; tag.
If you have access to a web site,
try it yourself.
End your filename with ".html",
and type in a bunch of paragraphs,
using &lt;P&gt; wherever you want a new paragraph to start.
Then try looking at it from any browsers you have available.