What does it mean if an iPhone is Locked to Rogers?

Additionally, would I need to unlock it? And how would I do so?

That means it will only work on the Rogers network, you won't be able to use it on any other network unless you get it unlocked. To get it unlocked, you will need to contact the network it is locked to. Rogers currently charge $50 - http://www.rogers.com/web/support/wireless/unlock/733?setLanguage=en

THIS IPHONE WAS PROVIDED BY THE Wi-Fi SUPPLIER CALLED ROGER LTD, AND IT WAS RESERVED TO BE USED ONLY FROM ROGER'S CUSTOMER.