Ransingh, welcome to Tom's Hardware Forum!
What is your question?
If you want to know how the motherboard gets its power, it is by plugging-in the 24-pins connector from the Power Supply to the motherboard. And the is also a 8-pins (4-pins on some motherboards) connector to supply power to the CPU. Both these connectors must be plugged in securely until the latch engages. The 24-pins connector is a little hard to plug in.