The column block is a unique columns block child. It acts like the div block and offers the same customisations.
This means that it cannot exist on its own but must be inserted into a columns block.
  1. 1.
    Open the Inserter Panel
  2. 2.
    Search for the
    column block
  3. 3.
    Click on the block to insert it into your parent block

Grid Layout tab

The Grid Layout