Connecting the Power and Turning on the Raspberry Pi
The last thing you should do is connect the power. The Micro USB power socket can be found in the bottom-left corner of the board (indicated in Figure 3-1).
The Raspberry Pi has no on/off switch, so when you connect the power, it starts working. To turn it off again, you disconnect the power. Sean plugs his USB hub and Raspberry Pi into power sockets on an extension lead, so he can switch them both on simultaneously by switching on the power to that extension lead. It’s less clumsy than removing or inserting the plug in the wall socket or the power lead in the Raspberry Pi all the time.
When you switch on your Raspberry Pi, the screen shows a rainbow of color briefly, and then starts to run the Linux operating system software on the SD card. The first time you switch on the Raspberry Pi, you feel a thrill to see it working, followed by nerves that you don’t understand all the text shooting up the screen. The text tells you what the Raspberry Pi is doing as it starts up, but you don’t need to know or worry about this. It takes a short while for the Raspberry Pi to finish starting up.