In addition to setting the dimensions of implicitly-added rows and columns, we can specify the order in which they are rendered.

grid-auto-flow specifies whether new elements should be added to rows or columns, and is declared on grid containers.

grid-auto-flow accepts these values:

• row — specifies the new elements should fill rows from left to right and create new rows when there are too many elements (default)
• column — specifies the new elements should fill columns from top to bottom and create new columns when there are too many elements
• dense — this keyword invokes an algorithm that attempts to fill holes earlier in the grid layout if smaller elements are added

You can pair row or column with dense, like this: grid-auto-flow: row dense;.