Line and Load
You may be not familiar with the electrical term line and load, which means the power connections coming into or out of electrical devices in the scheme of your electrical system. You see, the incoming feed from the utility company comes into the line side of an electric meter. It leaves the meter from the load side and then feeds the line side of a disconnect or electrical panel.
In the case of the disconnect, used to interrupt the power after the electric meter, the power comes in on the line side and out on the load side. The power is then fed to the home's electrical panel. The electrical panel also has a line and load connections. The line feeds the main breaker in a circuit breaker panel or a set of cartridge fuses in a fuse panel.