A blog (a contraction of the term web log) is a website, usually maintained by an individual, with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in reverse chronological order.
That’s how Wikipedia defines a blog. Apple doesn’t have an official blog and, according to reports, even goes to great lengths to prevent some employees from blogging about Apple on their personal time.
Furthermore, while Apple employees are granted permission by Apple to create their own personal Web pages and blogs, they are not allowed to comment on anything related to Apple on such pages. Furthermore, they are prohibited from posting in any capacity on any Mac-related Websites or forums, whether they identify themselves as working for Apple or not.