HTML tags are simply the markup language that tells the web browser how to display certain elements. Once you have mastered the basic HTML tags you will find it easy to start creating you own web pages.
Some sample HTML tags include the <html> tag, which tells the browser to start reading and parsing the HTML code.
<i> is used to display text in italics. Similarly, <b> is used to make text bold.
Most html tags are used in conjunction with a closing html tag. For example, at the end of your page you will use a </html> tag. Note the backslash. This is what tells the web browser that that particular html tag is now closed.