Does iMessaging use data? IPhone 4S?

I just got an iPhone 4S, but I didn't get a data plan with it. I can only use data if I am connected to the wifi.
But since iMessage is like text message I assumed it was free also, but i did some research and it says it will use your data.
Can someone clear it up for me? Thanks

That's right. Imessage requiress data and or wifi

IMessage uses your Texting plan, not data.

IMessage is free if you have free internet. The reason why people say you will be charged, is the use of data from your plan. If you have wifi connected, it will not use your data plan, instead use the available wifi.

I dont have a plan, and use prepaid on my iP5. I always have wifi connected in my house so i receive, and send iMessage for free. Only when im out of the house is when it asks me to connect to a data service.

Just remember iMessage is litterally email from apple. But uses your apple account to send to another apple account. So emails are free, but if it needs to be sent and there are no free internet (wifi) available, it will use your data or charge you extra because it uses data.

if you try to send iMessage to a phone number, or someone who does not have iMessage, it will convert as SMS and depending on your plan, or network, they will charge you as SMS.

You can use it via wifi, people do this when traveling when they have data shut off, imessage will use wifi if available. Yes imessage is free even if sent internationally.