Three types of notices can be sent under section 143 (1)
Intimation where the notice is to be simply considered as final assessment of your returns since the CPC or assessing officer has found the return filed by you to be matching with his computation under section 143 (1).
A refund notice ,where Income tax refunds you for extra tax paid, then you can look forward to the cheque.
Demand Notice where the officer’s computation shows shortfall in your tax payment. The notice will ask you to pay up the tax due within 30 days.