Eva Ferreira smacks down a few myths about CSS grid before going on to demonstrate some of the concepts of each:
❌ Grids arrived to kill Flexbox.
❌ Flexbox is Grid’s fallback.
Some more good advice about prototyping:
The best way to begin thinking about a grid structure is to draw it on paper; you’ll be able to see which are the columns, rows, and gaps you’ll be working on. Doodling on paper doesn’t take long and it will give you a better understanding of the overall grid.
These days, if you can draw a layout, you can probably get it done for real.