HTML stands for Hypertext Markup Language, and it's the formatting language used to build websites. In fact, http:// stands for Hypertext Transfer Protocol.
See how that works!
You use HTML Tags in your editor to generate the HTML code. The browser then translates the HTML code into the visual representation you see on your screen.
Of course you can do the same things in the Compose editor on Blogger. You can even upload from word or another web editor and never worry about HTML tags.
And the readers respond: "What's your point, Eric? You just said I don't need to know HTML to compose my blogs."
You don't.
But what about comments on other blogs? No "Compose" tab there. What if you want to add a link-back to one of your blog posts!
What about adding flair to your sidebar menus. Take a look at my Required Reading and Links and Publications and Works to your right. See the italics? See the web links? See the image of my book? I did that with HTML. No editor there.
In fact, the Required Reading section is entirely composed of HTML, from an editor, because it's the HTML/Javascript Gadget you can add from blogger.
HTML is defined with TAGS. TAGS are enclosed within the less-than and greater-than signs on your keyboard. <open TAG> Your Text </close TAG>
Each tag requires an opening and a closing tag. Note that on the closing tag, a slash / is used.
For example, this is the tag for a hyperlink: <a>link</a>
Text between the tags is displayed on the browser according to industry standards.
In blogger, you can also swap between Compose and Edit HTML to see the markup text and get some ideas there. I do this all the time.
Some BASIC HTML TAGS
<hr> Forces a horizontal break point, as above. I didn't find this one in blogger's Compose editor.
<i>ITALICS</i>
<b>BOLD</b>
<u>UNDERLINE</u>
Hyperlinks and Images require a reference inside the tag, href and src respectively.
HYPERLINKS
<a href="http://diggingwiththeworms.blogspot.com/">HYPERLINKS</a>
IMAGES: Height/Width in pixels, or leave blank. Note that this tag has no closing tag.
<img src="yourimage.jpg" width=250 height=200>
or to display without changing the size
<img src="yourimage.jpg">

SANDWICHING
You can sandwich your HTML tags by combining them together. For instance, you want an italicized web link:
<a href="http://yoursite.com/"><i>HYPERLINKS</i></a>
gives you: HYPERLINKS
Going into more detail is beyond this scope. Google HTML Tags if you want more information. My intent is to show a few basic formatting tags that help with your posting and blog management.
For a great post on customizing your BLOG, check out Jon Paul: Sky Blogs
CHALLENGE
Add a BOLD HYPERLINK to your comment linking back to your website. Use your preview feature to ensure it is working properly before saving.
Hope this helps improve the look and feel and usefulness of your future posts!
- Eric