The advantages and disadvantages of writing & phoning

This would is so big and also thid world is so small. When I want to connect with an old friend,usually I like talephon him at anytime." hello,Jack,how are you today?It's fine,well,I want to tell you a secret ,long time ago ,I ......" Suddenly , waking up to the secret might not said in word but only wrote in mail . So I said " Jack ,just a moment , I send you a mail." The advantages and disadvantages of writing & phoning, whether or no ,I like mail even more .