A socket for a connector , the socket comprising: a socket housing having substantially a rectangular shape having a width in a width direction (Y) and a length in a longitudinal direction (X), a socket-side signal terminal disposed in the socket housing , a socket-side power source terminal disposed in the socket housing , and a socket-side holder bracket disposed in the socket housing ; wherein, while the socket housing is engaged with a header housing , the socket-side signal terminal contacts a header-side signal terminal , and the socket-side power source terminal contacts a header-side power source terminal , wherein the socket-side holder bracket includes a mounting terminal configured to be soldered to a circuit pattern formed on a circuit board , wherein the socket-side power source terminal includes a base part configured to be soldered to the circuit pattern formed on the circuit board , and wherein the mounting terminal and the base part are configured to be soldered to a common circuit pattern , wherein the base part of the socket-side power source terminal protrudes from a side surface of the socket housing and the mounting terminal protrudes from the side surface , and wherein - the socket-side signal terminal and the socket-side power source terminal are arranged in the longitudinal direction (X) of the socket housing , - a width of the socket-side power source terminal in the longitudinal direction (X) of the socket housing is larger than a width of the socket-side signal terminal in the longitudinal direction (X), characterized in that the socket-side holder bracket and the socket-side power source terminal are adjacent to each other. a socket housing having substantially a rectangular shape having a width in a width direction (Y) and a length in a longitudinal direction (X), a socket-side signal terminal disposed in the socket housing , a socket-side power source terminal disposed in the socket housing , and a socket-side holder bracket disposed in the socket housing ; wherein, while the socket housing is engaged with a header housing , the socket-side signal terminal contacts a header-side signal terminal , and the socket-side power source terminal contacts a header-side power source terminal , wherein the socket-side holder bracket includes a mounting terminal configured to be soldered to a circuit pattern formed on a circuit board , wherein the socket-side power source terminal includes a base part configured to be soldered to the circuit pattern formed on the circuit board , and wherein the mounting terminal and the base part are configured to be soldered to a common circuit pattern , wherein the base part of the socket-side power source terminal protrudes from a side surface of the socket housing and the mounting terminal protrudes from the side surface , and wherein - the socket-side signal terminal and the socket-side power source terminal are arranged in the longitudinal direction (X) of the socket housing , - a width of the socket-side power source terminal in the longitudinal direction (X) of the socket housing is larger than a width of the socket-side signal terminal in the longitudinal direction (X), characterized in that the socket-side holder bracket and the socket-side power source terminal are adjacent to each other. - the socket-side signal terminal and the socket-side power source terminal are arranged in the longitudinal direction (X) of the socket housing , - a width of the socket-side power source terminal in the longitudinal direction (X) of the socket housing is larger than a width of the socket-side signal terminal in the longitudinal direction (X), characterized in that the socket-side holder bracket and the socket-side power source terminal are adjacent to each other. <EOS>