In the book Understanding Comics, by Scott McCloud, he thoroughly explains every aspect of comics, trying to persuade his discourse community, which is everyone, that they need to read comics and change their opinion of them. McCloud's purpose of writing the book was to spark conversation and debate of the things that he stated, when however that was not the effect of the book. McCloud wrote the book so well, that nobody argued with the content, and that was that.
McCloud prompted to write another book, almost ten years later that had a different purpose then his first book, he begins with the Introduction:12 revelations, which talked about how he wants comics to reach their full potential, and he proposes how we might be able to make that happen. One example he uses, is to expand the genres of what comic book authors write about, he believes that they need to venture our from talking about just super heroes, because the audience is potentially limited. He believes comics are very similar to film, because comics and film both use time to create a better story, McCloud is very realistic and realizes that film will most likely always be more popular then comics, but he explains that comics can potentially be not that far behind the popularity of film.
In chapter three of Understanding Comics, McCloud explains all the different types of panel to panel transittions that create time. The difference between the two books is that McCloud is informing in the book Understanding Comics, where as in The Introduction to his next book, he talks about the importance of time, but he doesnt inform the audience the importance of panel to panel transition, instead he explains the importance of time to help the whole genre of comics to becoming more popular, so that comics can be as popular as they were in the mid 1990's.