hi Ronny,
we can tell a weblog is a place(website) that many people share many things. Similarly; I learned what it is from my 16 years old son.
to explain it better; i copied and pasted what it is in Wikipedia, the free encyclopedia.
A weblog, web log or simply a blog, is a web application which contains periodic time-stamped posts on a common webpage. These posts are often but not necessarily in reverse chronological order. Such a website would typically be accessible to any Internet user. "Weblog" is a portmanteau of "web" and "log". The term "blog" came into common use as a way of avoiding confusion with the term server log.
Blogs run from individual diaries to arms of political campaigns, media programs and corporations, and from the writing of one occasional author to the collaboration of a large community of writers. Many weblogs enable visitors to leave public comments, which can lead to a community of readers centered around the blog; others are non-interactive. The totality of weblogs or blog-related websites is usually called the blogosphere. When a large amount of activity, information and opinion erupts around a particular subject or controversy in the blogosphere, it is commonly called a blogstorm or blog swarm.
The format of weblogs varies, from simple bullet lists of hyperlinks, to article summaries with user-provided comments and ratings. Individual weblog entries are almost always date and time-stamped, with the newest post at the top of the page. Because links are so important to weblogs, most blogs have a way of archiving older entries and generating a static address for individual entries; this static link is referred to as a permalink. The latest headlines, with hyperlinks and summaries, are offered in weblogs in the RSS or Atom XML format, to be read with a feed reader. Using RSS,content ranges from news and personal diaries, to political campaigns, media programs and corporations which are posted on a common web page in periodic, reverse chronological order.
A weblog is edited, organized and published often through a content management system or CMS.
Best regards