What is Webtoon? Webtoon is a a web-based cartoon, first popularized in Korea in 2007. Naver Webtoon is the hottest Webtoon platform in Korea. In 2010 2010, Naver Webtoon launched Line Webtoon, global Webtoon platform that depends on readers to translate Webtoons from around the globe.
What do Webtoon`s precedents such as comics, manga, and manhwa have as a common factor? They’re print-based cartoons formatted in grids, panels, and gutters.

무료웹툰 Understanding Comics by Scott McCloud
As McClound explains, the organization of panels decided the flow of order in print-based comics.

Whereas we flipped pages in cartoons to advance in one grid to the next,Webtoons, allow us to scroll through panels to advance the story.

Tower of God Episode 207
This is actually the first panel of Tower of God, the most popular Line Webtoons.

Tower of God Episode 207
A straightforward scroll-down will land you with the next panel.
Basically, there is no such thing as grid in Webtoons.
Besides increasing accessibility through an online platform, Webtoon has introduced new likelihood of reader interaction.
The transition from flipping through pages to scrolling down a monitor screen has given more freedom to readers in terms of story tempo and flow. Absence of grid freed the genre of cartoon from the limitations of layout and gave authors more space to test out each panel.