Line Breaks are a simple technique that allow you to break a line where ever you like, say if you wanted to start a new line but did not want to end the paragraph then you would use a line break, below is an example:
<body>
<p>This is a paragraph and i want to break the line here<br />this text is now on the second line</p>
</body>
This tag gives you full control of when you went a line break to occur and will come in very helpful as you begin to build your page and require certain formatting on your text.
If you wish to separate your page with a line or Horizontal rule then you can use the <hr /> tag, this puts a line across the page where ever you put the <hr /> tag in your code. You can also control the height, width and color of the horizontal rule using another embed style like so:
<body>
<hr style="width:400px; height:10px; color:blue; />
</body>
In some occasions you will be unable to get the effect's you want by just using the line break tag, is this case you can use the <pre> </pre> tags which keep the exact format of the text as you type it in. The <pre> tags also format your text in a monospace font by default, but if you wish you can use another embedded style to change this like so:
<body>
<pre style="font-family:comic sans ms; font-weight:bold;">
This is my pre formatted text which will be displayed exactly as you type it
</pre>
</body>
A non breaking space can be used in between words that you do not want to be separated onto another line, if i wanted to write someone's name and i wanted it to stay together at all times, so there first name wouldn't display on one line while there second name wrapped onto the next line, i could use a   which is the code for a non breaking space in between there names this would then tell the browser that it can not break in between the two names and so forth displaying the two names together on the next line. Non breaking spaces are also used for formatting text such as creating indents, see below:
<body>
<p>Hello my name is Ben Dougherty</p>
</body>
<body>
<p>    This paragraph is indented with 3 non breaking spaces</p>
</body>