Electricity is delivered to your home as alternating current, but laptops and many other electronics use the simpler direct current. The power inverter on your laptop cord is responsible for switching current from alternating to direct.
Direct Current
Direct current (DC) electricity can be envisioned as flowing through conductive material in much the same way water does. The current moves through a circuit in one direction and at a constant voltage. This greater uniformity of current makes it ideal for powering laptops and other electronics.
