Flexbox is the commonly-used name for the CSS Flexible Box Layout Module, a layout model for displaying items in a single dimension — as a row or as a column.
In the specification, Flexbox is described as a layout model for user interface design. The key feature of Flexbox is the fact that items in a flex layout can grow and shrink. Space can be assigned to the items themselves, or distributed between or around the items.
Flexbox also enables alignment of items on the main or cross axis, thus providing a high level of control over the size and alignment of a group of items.
- CSS Flexible Box Layout Module Level 1 Specification
- CSS Flexbox Guide: