Bipods are commonly used on rifles and machine guns to provide a forward rest and reduce unwanted motion. They are also seen on other long-barreled weapons. Bipods permit operators to easily rest a weapon on objects, like the ground or a wall, reducing their fatigue and increasing accuracy and stability. Bipods can be of fixed or adjustable length. Some can be tilted and also have their tilting point close to the barrel's central axis, allowing the weapon to tilt left and right. Some designs also allow the weapon to be rotated side-to-side. There are three ways for bipods to be folded: away from the shooter, towards the shooter, or into a vertical foregrip.