I don't understand columns and percentage widths

[risalfajar]

Never used Niri before. I assume 4 visible columns means the screen will be splitted into 4 section (each 25%). But why is the column width presets uses custom percentages? Shouldn't it use something like 1-column, 2-column, 3-column, full-column?

And what about rows? I see the video in YT that you can have two windows in the same column.

Sorry if I misunderstood a lot, I'm a web dev and knows css grid, I thought it's the same concept. Please shed some light.

[BarutSRB]

1. Visible columns are equally split so 4 would be 25%, 3 would be 33% of the screen width.
2. Column width cycle presets are for the following coomands:

3. Default New Column Width is for people that want custom column width even if it overflows. 4. Rows you simple consume a window into the column to add more rows to that column by using move command opt+shift+right/left arrow.