It's short for Hyper Text Markup Language , the basic language of the Internet. Usually includes title and meta tags. This is where the title of your page goes. Some HTML codes require both an opening and closing.
Title is one, just keep reading, it'll make sense.
And I'm done giving heading information. This command opens the BODY of your page, the stuff that will be seen on the screen. There are more commands that can be used inside the BODY listed below. After you're done writing text and adding graphics to the page, you need to close the command. In the example of a simple HTML page, we didn't specify what we wanted it to look like.