For this short Unity Lesson, I teach you what the is Kinematic option does on the Rigidbody component in Unity. The is kinematic setting makes it so that the rigidbody object will not move because of Physics.
Now you might be wondering, why would you want to attach a rigidbody component to an object only to disable to physics of the object? The answer is that sometimes you want an object to be stationary until a certain point and only after something happens do you want the object to interact with physics. At that point, all you have to do is disable the is kinematic option.
For example in my Zig Zag tutorial series I want the platforms to eventually fall but not until that ball touches the platform and then leaves the platform. This will then make it look like all the platforms are falling just behind the ball.