what is the difference between an ipod touch and an iphone?

okay, besdies that fact that u can use an iphone as a cell phone what is the difference with that and an itouch ipod?
with the itouch can i use the internet, download games, stores pictures, does it have a camera feature? and most importantly does it have a speaker like the iphone or does it have to be plugged into something in order to hear anything?

One is a phone, while the other is a multimedia player.
Other than video/regular calling, there are internet and other wireless components that iPhone has that iPod touch doesn’t.

Logitech Pure-Fi Anywhere 2 iPod/iPhone Speakers unboxing