incorrect. outstanding balance is whatever balance you still owe to the bank. It can include spending in the statement balance, either fully or partially.

if you want to avoid interest, you have to pay off whatever spending up to the statement date. You cannot just rely on outstanding balance to gauge this, because sometimes if you see outstanding balance is less than statement balance, people assume they have paid off the statement balance, which is wrong 

im still confusing , which one is actually i need to pay ? or its it combined together ?

AFAIK outstanding balance is the ACTUAL balance i owned from bank

is statement balance just a reference or some sort ??

outstanding balance can be less than statement balance due to cashbacks 

some users can be confused, because people advice them to just pay the statement balance. Then they would have overpaid 

Simple scenario:

Statement balance: RM500

Cashback (before interest due date): RM100

Spending after statement date: RM500

What is shown in the outstanding balance: RM900

What you should pay to avoid interest: RM400 (not statement balance, not outstanding balance)