Unlike documents in most word processors, carriage returns in HTML files aren't significant. In fact, any amount of whitespace -- including spaces, linefeeds, and carriage returns -- are automatically compressed into a single space when your HTML document is displayed in a browser. So you don't have to worry about how long your lines of text are. Word wrapping can occur at any point in your source file without affecting how the page will be displayed.
In this bare-bones example, the paragraph is coded as:
<P>Welcome to the world of HTML.
This is the first paragraph.
While short it is
still a paragraph!</P>
And the output is displayed as:
Welcome to the world of HTML. This is the first paragraph. While short it is still a paragraph!