What is income tax declaration and what is proof of investments?

Income Tax (IT) Declaration:

In the beginning or during the financial year, you declare all the IT saving investments and expenses that you’ve planned for that year in your Payroll application. This process is known as IT Declaration. 

Proof of Investments (POI):

Towards the end of the financial year, you are required to submit the proofs of your actual investments and expenses to corroborate your IT declaration. Your employers or approvers will process these proofs and calculate tax accordingly.