One of the meanings of “log” is to write an official account of an event. In ships for example, captains keep an official written account of what happens each day — this is called the captain’s log. In the old days, logs were maintained in ledgers; nowadays, they are saved on computers. “Blogging” is actually the short form of “web logging”. Like a diary, a blog may include anything — personal opinion, comments and experiences. Unlike a diary, however, a blog is written for others to read and comment on. You upload whatever material you have written onto the web, and you keep updating it on a regular basis. A person who writes blogs is called a “blogger”.