Wording.

Shelf

A horizontally scrolling row of items inside a vertically scrolling page, presenting one category per row — the pattern popularized by streaming apps.

Example usage
Each genre gets a shelf, so the home screen surfaces ten categories without ten screens of scrolling.
Editor’s note

Shelves trade visibility for breadth: every category is present, but most items hide off-screen. They work when categories matter more than items. If users come looking for one specific thing, horizontal scrolling is friction — give them a grid and a filter.