Weblogs are basically journals, with the most recent entry at the top of the page, much like how topic threads are arranged on message boards.
Many blogs are personal, but you're hearing more about them because many people have been using their blogs to post and comment on news, events, media, politics, and so on. They're significant because they allow ordinary people to criticize flaws in traditional media coverage. They uncover errors, bias, and outright lies.
A good example of that was
www.andrewsullivan.com who relentlessly pointed out the awful quality of NY Times's editor, Howell Raines and how he turned the entire paper into a propaganda organ for leftist causes. He also had great criticism of the terrible anti-American bias of the BBC. And he had the satisfaction of watching both Howell Raines and the BBC examined and punished for violations he had been complaining about for years.
Some blogs have specific areas of interest. For
Kim Du Toit, it's guns. For
Charles Johnson it's Islam, Israel, and the war on terrorism. For
W, it's the vile nature of the French media and translating the hateful anti-Americanism of its journalism, as well as negative aspects of The World's Most Civilized and Superior Nation. For
Wretchard it's military operations, tactics, and the war on terrorism. For
Donald Luskin, it's refuting and pointing out the lies and distortions of Paul Krugman's NY Times editorial columns. For
Alhamedi, it's about life for a sane, thoughtful, sophisticated man who lives in Saudi Arabia.
The most widely read, generic, news-related blog is
www.instapundit.com, written by Glenn Reynolds, a law professor.
Blogs seem to be overwhelmingly right-wing. Many got their start after 9/11 and the war began. Some had been around, but were apolitical, like
www.littlegreenfootballs.com.
It sounds pretentious, but blogs are becoming a hugely important part of the internet and challenging the media, forcing them from their arrogant assumptions of what they deem to be news and what the real story is. For example, there are DOZENS of blogs done by soldiers and Iraqi citizens who point out how the media completely ignores any positive progress in Iraq, but exaggerates and focuses on the negative and the violence. Blogs and the internet give another perspective than that of the professional journalist. It gives a loudspeaker to ordinary people, unfiltered by editors or commercial or political considerations.