If i buy an unlocked phone on ebay can i use an orange pay as you go sim card with it?

I'm thinking about purchasing an unlocked phone on ebay and putting my current pay as you go sim card in it. However, i'm not sure if this is possible because the phone isn't branded with the orange network, does this matter?
In the information for the unlocked phone on ebay it does state

"Network bands: HSPA/WCDMA: 850/900/2100 MHz
GSM/GPRS/EDGE: 850/900/1800/1900 MHz"

I'm not sure if that'll help you answer my question but i've heard it has something to do with it.