A blog (short for web-log) is an easily updatable web page that displays entries in chronological order (like this one!), essentially working like a diary or a newsletter. Early blogs were often personal journals, but the format and ease of use has led to them being adapted for all kinds of purposes - news sites, opinion blogs, travelogues, basically anything where new content is to be added while maintaining the old as an archive.

Blogs have a couple of other features which make them a powerful way of distributing new content. One is comments, where each post can be commented on by those who read it, allowing for feedback and further discussion. The second is RSS feeds (more to come on those next week!), which mean that readers can subscribe to the blog and be notified of updates. Feeds can also be used to publish the blog content on other websites without having to update them separately.

To see some of the features of blogs in action, take a look at some of the following:

Blogs are updated and usually hosted on a dedicated blogging website, although they can be made to look like they are hosted on your own site. Major blogging sites include Blogger, Wordpress, Typepad and LiveJournal. This blog is hosted on Blogger (note the blogspot.com address). We have decided to use Blogger for the 23 Things programme as it is owned by Google and you should all have Google accounts from last week's things if not before.