The pressure is lower in a moving fluid than in a stationary fluid. This effect is called the Bernoulli effect. If you put the convex side of a spoon into a smooth stream of water from the faucet, you will feel the spoon pulled into the stream. The higher pressure outside the moving fluid pushes the spoon into the lower pressure water.
A ball balances in a stream of air from a blower. The ball is strongly held in the lower pressure stream of air.
