JST Connectors

JST is a manufacture of low cost PCB plug and sockets.  

The manufactures web site is:

The NMRA has standardized on the right angle (9x1) 9 Pin version for a decoder connector.  It offered as an alternative to the older straight up (4x2) 8 pin socket.   In addition many other decoder manufactures use the JST connector in other pin count versions for other purposes.

There are two parts to the connector system.  The Socket and the Plug.   The socket is typically mounted on the PCB and has male pins.   The plug typically has the wires and uses female pins (pin sockets) which form a plug in cable assembly.