Spacing and formatting
Whitespace is characters such as space, tab or return (Enter).No matter how many whitespace characters you put in a row, or which ones you use, the browser will only show one single space.
Line breaks, forced new line
If you want to force a line break use the tag <br />.
the text following the <br /> tag will continue on the next line.
Don't use a <br / > tag at the end of every line. Let the browser wrap your text for you to fit. You don't know how wide the visitor's browser window is and your line lengths may not work well for them.
Use a <br /> tag when you deliberately have short lines, such as in poetry.
Paragraphs
Begin paragraphs with a <p> tag and end them with a </p> tag. The browser will automatically skip a line between paragraphs.
In HTML people often used to put a <p> tag between paragraphs to separate them, this is not correct in XHTML. Even in HTML, if you put any attributes in the <p> tag, then you will need a closing </p> tag. (Attributes are things like align= which will be discussed later.)
"pre" formatted text
You can force the format, including extra spaces and line breaks to be exactly as you typed it, by putting it in-between <pre> and </pre> tags. As you can see <pre> causes the font to change to monospaced.
Blockquote
<blockquote> tags are intended to indicate a chunk of quoted text inserted into your document. this tag will cause the enclosed text to all be indented, always on the left side and in some browsers on the right side also.
The material in the blockquote can be several paragraphs long.
Just be sure to end with a </blockquote> tag when you are done.