An "h" tag is used for titles and important subtitles. There are 6 versions of the h tag. They are h1-h6

This is a paragraph tag It is used for writing sentences and paragraphs. Paragraph tags automaticlly insert a line break everytime they are used.

This is a span tag It is also used for writing sentences and paragraphs, however span tags do not insert a linebreak everytime they are used. 
This is a pre tag. It is used to display pre formated text. Pre tags will keep the font family of the source of the text.
An "a" tag is a link to a different web page.

Here's how to make a unordered list:

Here's how to make an ordered list

  1. First thing
  2. Second thing
  3. Third thing

Div tags are used as dividers. You use them to seperate page/documents sections.

This is a center tag. it is used to center content on the webpage.

This is a marquee tag. It is used to make text move across the screen forever