HTML is hypertext mark up language.
Hypertext means it uses links to connect the pages
Mark-up means you type in the words and them "mark them up" to show how to display them.

You type in the text and mark it up with tags.  The tags are all enclosed in angle brackets. < >

Some tags are one-sided, some two-sided. 

A one-sided tag is something like <hr> for horizontal rule that places a line across the page

A two-sided tag has an opening tag and a closing tag.  The opening tag turns on a feature and the closing tag turns it off.  For example <b> is the tag to turn on bold print and </b> is the closing tag to turn off the bold print.

Special symbols that are not available on the keyboard can be entered using the & followed by a special code.  For example &#169; is the code to place a copyright symbol on a web page.

It does not matter how you space your words in the original HTML code because all extra spaces and carriage returns are ignored by the browser when it displays the page. To put extra blank spaces on the page type       &nbsp; for a non-breaking space.