What is "Purchase *Finance Charge* Periodic Fate"?

i have it on my credit card bill charged me $4.50 on top of my monthly statement.

that's is the interest that u occurred on the balance you carry if u pay ur balance off before you billing cycle end u will not incur any finance charges also look out for annul fee if u are planning on carry a balance i recommend looking for a a card with a long promotional 0% interest rate on purchases and a low rate and no annul fees