What is BodyGyro, and BodyPosition? [UNANSWERED]

I've been seeing this in scripts of hopperbins, such as ones that spawn a sphere(Yes, a specialMesh) and damage you for each second. So I search up the wiki, and did not explain it good enough xD.

 xWalkSpeed = humanoid.WalkSpeed
   Gyro = Instance.new("BodyGyro")
   Gyro.Parent = torso
   Gyro.D = 50
   Gyro.maxTorque = Vector3.new(0, 0, 0)
   Gyro.cframe = torso.CFrame
   Velocity = Instance.new("BodyVelocity")
   Velocity.Parent = torso
   Velocity.maxForce = Vector3.new(0, 0, 0)
   Position = Instance.new("BodyPosition")
   Position.Parent = torso
   Position.maxForce = Vector3.new(0, 0, 0)
   safe = humanoid.Health
    wait(0.05)

You see, all I know is the BodyVelocity used for projectiles, but as for the others, I'm not familiar with it.