WTB (Wire to Board) connector: used for connecting wires to circuit boards, i.e. “wire to board” connection. It connects external wires (such as power lines and signal lines) to the PCB board to achieve signal or power transmission.
BTB (Board to Board) connector: used for direct connection between two circuit boards, i.e. “board to board” connection, without the need for cable intermediaries, commonly used for stacking or parallel connection between the main board and the sub board.
For example, the camera module in a mobile phone is connected to the motherboard through an FPC cable, which belongs to the WTB category; The direct connection between the motherboard and the display driver board often uses BTB connection.