The most common difference between a blog and a web page or even post on a forum is usually the style of text in a blog is casual, informal and personal.
While one usually review the text posted on a website or a forum, the nature and style of blogs, give us greater flexibility and informality, as readers know that a blog is nothing more than a set of notes or annotations we are doing in a journal we share.
The blog entries often or may be quite short. Although a blog can also be a set of well-developed texts and even not so short.
Also, it is quite common in blog entries are chronological, the style of a blog that recounts our daily lives or process. But blogs are common in which entries are thematic or even “psychic” and have little to do with time or day it is made.