I am confused because i am not sure what does a powerstation transmit and the notes mentioned something about transmission of potential difference. Since the potential difference at the primary coil in a step down transformer is high why does it have a low current and vice versa at the secondary coil as i thought high potential difference results in high current but i get the part that power should be a constant at both sides of the transformer
At the power station, the output of the generator is connected to the step-up transformer primary. this maximizes the voltage and minimizes the current- which minimizes the power losses in the transmission line.
At the other end of the transmission line, a step-down transformer primary is connected to the power line and its secondary is connected to the local power distribution system. This transformer brings the voltage back down and raises the current back up again.
The two things to remember are this: 1) transformers conserve power (power in = power out) which means if a transformer kicks up the voltage it also kicks down the current at the same time, and 2) power = voltage x current no matter what.
i thought high potential difference results in high current
All other things being equal, you're correct. For a circuit with a resistive load, higher voltage (higher potential difference) does mean a higher current.
If the power station were to increase the voltage it supplies slightly, the current in both sides would increase. It's just that the ratio of the currents will be constant.
You can think of the transformer like a lever. We want to lift a rock. A lever lets us use less force to lift it, but it means we need to move our lever at a higher speed than the rock. The ratio between the forces on both side (and the speed of both sides) is constant.