A HTML page is made up of a set of HTML Elements. HTML elements consist of HTML Tags and some content.
The following is an example of a HTML element.
<h1>A very interesting web page!!!</h1>
<h1> and </h1> are the tags in this HTML element and it tells the web browser to display the text - A very interesting web page!!! - as heading.
Most of the HTML tags come in pairs - an opening tag and a closing tag.
Opening tags will have a < followed by the tag name and >
Closing tags will have a < / followed by the tag name and a >
In the HTML element above, <h1> is the opening tag and </h1> is the closing tag.
Some HTML tags do not have a closing tag. For example the <br> tag is used insert a line break in a HTML page and it does not require a closing tag.
The opening tags in HTML can have attributes which provides additional information to the tag.
The <font> tag in your first html page has the attribute color=red to display the text in red.