Why is it that the VAT control acccount's debits and credits are the opposite?

So I keep getting confused as to why when VAT is calculated and goes into the VAT Control Account, that:

• the balance c.d. on the debit side shows what we need to pay to HMRC
• the balance c.d. on credit side shows what we can reclaim from HMRC.

I don't understand this because in my head, debits come into the business and credits come out of the business. But in the case above, it is the opposite.