This document discusses CSS Grid Layout and provides examples of how to define grids and place items on grids. Some key points:
- CSS Grid Layout allows dividing available space into columns and rows to position elements.
- Grids are defined on parent elements using properties like grid-template-columns, grid-template-rows, and grid-template-areas.
- Child elements can be placed on the grid using line-based placement with properties like grid-column and grid-row, or by targeting named lines and areas.
- Grids can be redefined at different breakpoints to create responsive layouts without changing HTML structure.