Dreamweaver MX 2004 help please

Since recently upgrading to the 2004 version of Dreameaver The are a couple of HTML tags that are new to me and I cannot find out what they are for.

First there is the <th> tag. I know it has something to do with tables but I can't find anything to distinguish it from the <td> tag.

The other one I cannot find anything about is the <scope> tag.

Could someone please enlighten me as to what these 2 tags actually do. What they are for and when they should be used.

All help much appreciated

the th tag is when you want to declare a header cell (to make some text stand out), it really isn't used much any more but more info can be found about the th tag, and the attributes that can go with it, such as the scope. click here (http://www.w3schools.com/tags/tag_th.asp)