How do I make a beam that follows the player mouse?

In the recent Power Simulator game, there is a power which allows the player to shoot a beam from their hands. This beams smoothly follows the mouse position. How is this achieved?

I have an idea where the server invokes the client for their mouse position and the server then creates the beam using the mouse position which was invokes, I can imagine this happens every wait() but wouldn't that put strain on the server script?

Note that everyone in the game can see this beam so therefore isn't a client only job.