A blog (short for “web blog”)  is a discussion or information site that is published on a global network consisting of discrete, usually informal, diary-style entries (posts). Posts are usually displayed in reverse chronological order so that the last post appears first, at the top of the web page. Until 2009, blogs were usually the work of a single person,  occasionally of a small group, and often covered a single topic or topic.
In the 2010s, “multi-author blogs” (MABs) emerged, which included the writing of many authors and were often professionally edited. MABs from newspapers, other media outlets, universities, think tanks, advocacy groups and similar institutions are responsible for an increasing amount of blog traffic. The rise of Twitter and other “microblogging” systems is helping to integrate single-author MABs and blogs into news media. A blog can also be used as a verb, i.e. maintain or add content to the blog.
The emergence and growth of blogs in the late 1990s coincided with the advent of online advertising tools that made it easier to publish content by non-technical users who had little experience with HTML or computer programming. In the past, knowledge of technologies such as HTML and File Transfer Protocol was required to publish content on the Web, so early Internet users tended to be hackers and computer enthusiasts. In the 2010s, the majority were Web 2.0 interactive websites,
Which allow visitors to leave comments online, and it is this interactivity that sets them apart from other static sites.  In this sense, blogging can be seen as a kind of social networking service. Indeed, bloggers not only produce content for advertising on their blogs, but also often build social connections with their readers and with other bloggers.  However, there are reader-intensive blogs that do not allow comments.