Arduino + Relay Explanation

thanks for the reply.

BTW what if i use a SSR which will give me a current output of only 1A MAX, as i need to light up a bulb which is only 60WATT and according to the following

P = IE
I = P/E = 60/100 = 0.6A

So i think i can use a SSR with following attributes

IN: 4~7VDC
OUT: 100~220VAC
Current OUT : 1A Max

Whats your say on this?