Compared to traditional gardening methods, plants are spaced closer together (so that their leaves touch) and you can stagger your rows to fit more plants in a smaller area.
Not only does this increase your yields, it also protects the soil by using the plants themselves as mulch for neighboring plants. When there’s less space available, weeds have less opportunity to take hold.
One thing to keep in mind is if you direct sow seeds in a raised bed, you should sow them a little more densely to account for varying germination rates.
Once the seedlings are a few inches tall (and it’s easier to see which ones are stronger and healthier), you can thin them to the appropriate spacing.
For example, cabbage needs 15 to 18 inches of space between plants, but you’re better off sowing seeds every 4 to 6 inches to ensure good germination. For thin-skinned seeds like snap beans, soak for 2 to 4 hours.