I think it's interesting that, while a lot of people struggle with the concept of a graphic novel (compared to a comic book), the idea of webcomics is far easier for non-comic-readers to understand.
And I can see why: It's the same idea as a daily comic in the newspaper, except it's online. But there are some huge differences between the two.
(To clarify, I'm comparing webcomics to the comics you see in the newspaper, not comic books. That's a whole different animal I'll probably tackle at some point in the future.)
1. Webcomics don't have to be censored.
Newspapers arrive at a wide variety of homes, many of which house children, who aren't supposed to see bad words or nudity or adult themes like drugs and violence, so these don't appear in newspaper comics. But webcomics are usually self-published. They appear on their very own websites, usually run by the authors themselves. So they can be as bad as they wanna be, a la Dennis Rodman. All of my favorite webcomics have contained profanity at one point or another (although I think xkcd usually bleeps) and one (Menage a 3) has what I would categorize as excessive nudity.
2. Webcomics set their own schedule... and don't always stick to it.The webcomics I read on a regular basis are the ones that tend to keep to their scheduled post times. Webcomic authors don't have to answer to an editor or someone like that like the newspaper comic creators do. No, far worse... webcomic authors answer directly to the reader. And if you miss the mark too often, you lose readers. But, this also means they can work on the next day's comic up to the last second, whereas newspaper comics have to be submitted ahead of time in order to be rearranged, printed, bound, and shipped off to the houses where they will be consumed. Webcomics might have been completed 12 seconds before you read them if you have good timing.
3. You can interact directly with webcomic creators, and many of them blog along with the comics.>
Off the top of my head, I know that at least two of the webcomics I read regularly (Questionable Content and Least I Could Do) have blogs alongside them. I know this because I usually at least skim the posts, if not read them thoroughly. You can learn a lot about the creators that way, and see their lives peeking through (or bashing through, in some cases) in their work. Some people like that; some don't. Other webcomics, like this week's Hyperbole and a Half and The Oatmeal, are directly drawn from the creator's life/experiences. Newspaper comics might every once in a while include a message from the creator, but usually they stand alone. Personally, I feel way more attached to Jeph Jacques, Allie Brosh, Matthew Inman, Tycho and Gabe, and Randy Munroe than I ever was to Charles Schultz or Jim Davis. Better yet, WHILE I'm reading their work, I have direct access to them; I just emailed Allie Brosh a couple weeks ago! How cool is that?
What are some differences you see between newspaper comics and webcomics? Which do you prefer?