Hydroseeding is a technique that uses a slurry of water, fertilizer, and seed to spray onto soil. Hydroseeding is often used on large areas such as meadows, golf courses, and airport runways. The seeds in hydroseeding are usually larger than those in normal seeding, which means they can be planted at a greater depth and have a better chance of becoming established.

The two methods achieve different results - hydroseeding is best for establishing a uniform lawn with good coverage, while seeding is better for filling in bald patches or areas with thick grass. So it really depends on your specific needs and what you're trying to achieve.