How do I find out what a block style letter, and what a semi-block style letter is, and how do I see a picture of it?

Question

Here are some good illustrations and explanations:

http://englishplus.com/grammar/00000150.htm

http://jobsearchtech.about.com/od/letters/l/bl_block_p.htm

Be sure to scroll down on both webpages to see all the information and any pertinent links.

=)