HTML Pages can have what is called META DATA, basically information about your web page. These Tags are simply HTML which is placed between the <HEAD> and </HEAD> tags on your website.
If your website was called "Queen - The Best Band Ever", then your TITLE tag would be
<TITLE>Queen - The Best Band Ever</TITLE>
The title is very important to the search engine.
Extra tags can include keywords, description, author and robots, .... as follows.
<meta name="keywords" content="queen, band, group, freddie mercury, brian may, roger taylor, john deacon, queen website">
<meta name="description" content="Queen are the best band ever and this website has some good information to all Queen Fans">
<meta name="ROBOTS" content="index,follow">
<meta name="REVISIT-AFTER" content="8 days">
<meta name="Author" content="Your Name Here">
If you have any difficulty understanding any of this, I recommend you read up on HTML and its usage, because if one of these tags was mis placed it could result in your site showing all your meta data in the midst of the webpage.
See : http://www.htmlprimer.com