Heading level 1

Heading level 3

Heading level 6

Headers are typically rendered in boldface and cause a paragraph break in the page. By paragraph break, we mean a line break followed by a blank line. So, closing this paragraph

and starting a new one is equivalent to

which causes two line breaks as you can see. A horizontal rule

is a solid line and gives a vertical break in the page. The pre element not only gives a teletype (monospace) font, but preserves white spaces and blank lines. We have left it on the left margin so you can see that the indentions are preserved in the web page. As you now know,browsers ignore extra white spaces otherwise.

  for(x=1;x>0;x++){
  
    Caution, I am
    an infinite loop.
    
  }