Jacks, Plugs & PostsPosts located at convenient places are essential for efficient powering of any electrical device from a power source. Wires bound to posts on both the source and the device carry power from the power source to the device. A fixed electrical connector with a number of receptacles that can be used for any removable plug is usually termed a Jack socket. The removable plug is also referred to as a Jack plug. The plug and socket combination is known by several names like receptacles, connectors, etc.
The post is a connector attached to different points of electronic circuits. It is also used for the testing and measurement of voltages at the point. They can be commonly found in amplifiers, radios, etc.