Well, to begin with, they are Japanese fiction, stories made in Japan. Even the term "light novel," by the way, is a Japanese word, not an English word. (see wasei-eigo 和製英語)
Content of Light NovelsThe content of the novels can be pretty much anything, from happy slice of life to planetary genocide, but what makes light novels different from novels is that they are targeted to middle and high-schoolers, just like shounen and shoujo manga are.
What that means is that, light novels, contrary to ordinary novels, are filled with pop culture and anime references, stuff about games, otaku オタク characters, fujoshi 腐女子 characters, commentary about magical girls, and other stuff that appeals teenagers. Not to mention they are easier to read than novels meant for adults.
Examples of Light Novels
If you don't believe me, here's some proof. The light novels below all became anime, here's a synopsis of them (links to Amazon):
- Overlord オーバーロード
An MMORPG addict goes to the MMORPG world.
- Re: Zero kara Hajimeru Isekai Seikatsu re:ゼロから始める異世界生活
An otaku goes to a fantasy world.
- GATE: Jieitai Kanochi Nite, Kaku Tatakaeri ゲート自衛隊彼の地にて、斯く戦えり
An army otaku goes to a fantasy world.
- No Game No Life ノーゲーム・ノーライフ
A couple of twin otaku / hikkimori / NEET / geniuses go a fantasy world.
- Sword Art Online ソードアート・オンライン
A game addict goes to a virtual world.
- Yahari Ore no Seishun Rabu Kome wa Machigatteiru やはり俺の青春ラブコメはまちがっている。
A loser no-friends extremely anti-social high-schooler is forced to join a club.
- Suzumiya Haruhi no Yuuutsu 涼宮ハルヒの憂鬱
A guy who doesn't believe in aliens, time-travelers or espers gets a girlfriend who does.
Anyway, the light novels above are all about love comedy, or romance, or comedy, or adventure, or some stuff like that. They're all filled with all sorts of references only youngsters would get. They follow a formula which attracts teengaers and that's why they are light novels.
Light Novel LengthYour usual light novel has, like, a ton of words. Seriously. A ton. The first volume of the Overlord オーバーロード light novel, which I'll be using as metric because I don't really read these things, has just five chapters totalling 360 pages.
Now, 360 pages is a lot of pages. I don't even read books and I know that. But wait, these aren't English pages, these are Japanese pages, which kind of look like this.
As you can see... not as much text as you'd expect. Still, 360 pages is a lot of text. Specially given that is only the first volume and there are plenty of volumes. The light novels are serialized, which mean they just keep pumping out this stuff non-stop.
Your usual anime-to-be light novel is at least one book big. In English story books' metric. Okay, that doesn't sound very precise, but what I'm trying to say is that light novels shouldn't be taken lightly. They are actual, full, complete, huge stories, meant to be read through years of serialization. Like your usual manga series, except it has no pictures, just a whole lot of text.
Wait, did I say it has no pictures? That's not right.
Pictures in Light NovelsLike pretty much everything made in Japan these days, light novels usually have manga-style illustrations all over them. By which I mean about one or two manga-style illustrations per chapter or something about it.
Now, 100 pages of text per picture is a lot different from manga's 4 to 6 pictures per page, so they make it count. Most of the pictures in light novels are full-page illustrations of important scenes and characters, which help the average teenager visualize what the fuck these characters he has been reading about for the last hour look like.
Web Novels, WBLastly, while most light novels, LN, are published on paper, serialized, some light novels are not. Just like One Punch Man ワンパンマン started out as a very, very ugly web comic, which was miraculously turned into a gorgeous manga, and then into an amazing anime, some light novels follow the same path.
Such is the case of Re: Zero kara Hajimeru Isekai Seikatsu re:ゼロから始める異世界生活, which was first published online as a web novel, then tidied up and adapted as a light novel, then drawn and adapted as a manga, and then animated and adapted as an anime.
(am I the only one who thinks there is something seriously wrong with that?)
Anyway, web novels are novels of the future! And by future I mean present. You can start reading the Re:Zero web novel in Japanese right now if you want thanks to the wonders of the internet.