Socket connector and plug connector

The invention relates to a socket connector which comprises a connecting seat, a plurality of first terminals, a plurality of second terminals and a plurality of third terminals, wherein the connecting seat is provided with an opening; each first terminal is provided with a first contact part, and the first contact part is configured in the connecting seat and adjacent to the opening; each secondterminal is provided with a second contact part, and the second contact part is configured in the connecting seat and adjacent to the opening; each third terminal is provided with a third contact part, and the third contact part is configured in the connecting seat and adjacent to the opening; the first contact parts are virtually arranged in the connecting seat along a line segment; the second contact parts and the third contact parts are virtually arranged along a straight line; a projection of the line segment on the straight line is arranged between the second contact parts and the third contact parts and is not overlapped with the second contact parts and the third contact parts. The invention also provides a plug connector which corresponds to the socket connector and has a similar structure with the socket connector.