A "cord" is basically the same as a "wire", but with some small differences. A "cord" usually comes out of an electrical device and plugs into something else. You could call this a "wire" too, but "cord" is more common.
Inside of an electical device, there are probably a lot of small wires. You wouldn't call these "cords".
The word "cable" also describes a type of wire. A "cable" is longer and thicker than a cord. For example, electrical cables provide power to your home.