What constitutes Date Usage on an iPhone 5? I have an iPhone 5 and I just received notice that my data usage for free is almost up.  I presently have 1GB. I am total unaware of what data usage is and should I change to a plan with 2GB.

Do I have to do something to make sure I use Wi-Fi in all places that I am.

Exactly what takes up my data usage when using my phone? Is it from receiving a message, text, taking photos. Please be specific if possible.
You need to contact your Carrier, i.e. Verizon, AT&amp;T, Sprint etc, to see what they define as Data Usage.

That said, generally speaking, any communication that you send/receive/request over their network while directly connected to their network, and while Roaming, is typically counted under Data Usage.  This could be emails, websites, pictures, videos, etc. Typically when connected to a Wi-Fi Access Point then Data Usage Accounting is not counted against your monthly Data Usage allotment.