The utility company brings wires overhead to connect to electrical service via your feeder wires. These wires come in through your service pole via the weather head. The wires connect to the top side of the meter called the line side. There are two hot wires that are generally left black in color. The third wire is the neutral wire that is generally marked with white tape.
The two connection terminals on the top of the meter on the outside is where the hot wires will connect. If you look, it is where the meter will also connect. The connection terminal in the center is where the neutral will connect. Strip the wires and insert them into the terminal. Tighten the screws until they are tight and tug on the wires to be sure that the connection is tight.