Basically, a computer sees an “A” as simply an “A” – whether it is bold, italic, big or small.
To tell the browser that an “A” should be bold we need to put a markup in front of the A.
Such a markup is called a Tag.
All HTML tags are enclosed in < and >.
Example: a piece of text as it appears on the screen.
HTML: the HTML for the above example:
As you can see, the start tag indicates that whatever follows should be written in bold. The corresponding end tag indicates that the browser should stop writing text in bold.