Hi Veen,
Welcome to our community! 
Before I start explaining anything: Does your code work? If not, make sure the method names are spelt correctly. In the code you posted, the Update method must be called “Update” with a capital U.
Furthermore, the condition of the if-statement in the Update method must be (hasStarted != true); alternatively, (!hasStarted).
Our Update method gets called each frame. This means that the if-condition gets evaluated each frame, too. As long as the result is “false”, the if-block gets executed, and therefore also the LaunchOnMouseClick code block. And that’s how the ball gets locked to the paddle.
See also:
- Forum User Guides : How to apply code formatting within your post
- Forum User Guides : How to mark a topic as solved