What is the difference between VOIP phone, WIFI phone, bluetooth Phone?

YOU NEED A VOIP phone – skype is a package that allows you to use the internet connection to make phone calls for almost free… make sure you get one with a good microphone….A mobile WiFi phone that enables you (without a PC) to make free Internet calls to anyone else in the world who has Skype – but its much more expensive .. bluetooth is a wifi technology so wil be about the same high price…..gives more flexibility….

PS VOIP – "voice over internet protocol"