how a computer works when power is on

                                       Switch-on

As you see this heading is some kind of weird thing ,so many dont know how a operating gets started when laptop or computer is switch on.There are so many things in our computer like hard-disk,Ram,Rom,I/O devices.when a computer is switched on these things have to get the power at the same time,this can be possible by using of the SMPS.

   

                   SMPS is abbreivated as Switch Mode Power Supply.This SMPS is connected to all the Hard-Disk,RAM,ROM and I/O devices .The ROM is a non-volatile memory which has the starting address of the operating system.As is ROM is a non-volatile memory its does not loose its memory when the power is switched off.So ROM is used to store the starting address of the operating system.Actually ROM is connected to the BIOS.BIOS is Basic Input-Output System,it is first software run by the laptop / computer when it is powered on.The starting address of the operating system passed to the RAM.Based on that address it gets the operating system from the hard disk and loaded into the RAM,when the operating system is loaded we can see the screen on our laptop or computer.As long as the power is on the data in the RAM is safe. when the power is off the data in the RAM is erased because it is volatile.so it is not safe to store the starting address of the operating system.This is how a laptop works when the power is switched on