There is also air in your soil. The air is found in pockets between the minerals and organic matter. If you don't have enough air, your roots will not be healthy. Air can be forced out because of too much water. Water is also a necessary ingredient for soil.
Water is necessary for plant growth.
Plants need it just like we do. Water also carries nutrients through the soil. Organic matter is a requisite for healthy garden soil. It holds water, stabilizes the soil, holds nutrients and provides food for soil organisms. All the microorganisms in your soil help your plants.