A blog is like the diary you have on your site:
http://www.vickyathome.com/diary.htm
The difference is that you would put each entry for the day into the blog script (such as WordPress -
http://www.wordpress.com or Movable Type -
http://www.sixapart.com/movabletype/pricing ) and the script would format it for you, like this page -
http://www.wordpress.com/ - the front of wordpress.com is a perfect example.
Why are blogs hot now? Because search engines love to spider them and add the results to their listings; typically you can get more hits via that method than by post a gallery of pics and having it spidered. I think that blogs get preferential treatment from Google because they are dynamic rather than static, i.e. they update every day.
Nice seeing you at AVN Vicky!! Great pix
http://www.xxxpartycentral.com/vicky_vette.htm