The DIV and SPAN Tags

The < span > and < div > tags were introduce in the
HTML that are very useful when dealing with Cascading
Style Sheets or CSS. We tend to use them in similar fashion,
but they serve different purposes.
The < div > tag defines logical divisions in our Web page.
In terms of layout, the < div > tag does only one thing; it determines
the alignment of that section of your page. The < div > also gives you
the chance to define the style of whole sections of HTML. You could
define a section of your page as a call out and give that section a different
style from the surrounding text. The < div > tag gives you the ability to name
certain sections of your documents so that you can affect them with style
sheets or Dynamic HTML. One thing to keep in mind when using the < div >
tag is that it breaks paragraphs. It acts as a paragraph end/beginning, and
while you can have paragraphs within a < div > you can't have a < div >
inside a paragraph.
The < span > tag has very similar properties to the < div > tag, in that
it affects the style of the text it encloses. Items in the < span > can be
aligned or given specific style attributes. The primary difference
between the and

tags is that < span > doesn't do any
formatting of its own. The < div > tag acts as a paragraph break, because
it is defining a logical division in the document. The < span > tag simply
tells the browser to apply the style and align rules to whatever is
within the < span >.