VoIP originally stood for Voice over Internet Protocol. We largely still think of VoIP as voice but the V in VoIP also stands for video, or if you look at tagline for Jeff Pulver's VON Conference, it's "Voice, Video, Vision."

Much of the same technology that enables voice to travel over the Internet is used to make video go as well. The same protocols are used with different compression schemes more appropriate for the transmission of video. Some of the same providers that provide voice service also provide video calling services as well. There are also services that specialize in this, such as SightSpeed.

And then there is the whole plethora of online video sites like YouTube, Revvr, and Viddler that offer you the ability to share videos, or even SightSpeed's Blip, where you can interact in a forum-like manner with videos. These certainly transmit video over IP as well, but I wouldn't necessarily call them VoIP.

VoIP is a realtime connection between two or more people using IP. It's more than just words like Instant Messaging. It's about conveying feeling in your voice or seeing and hearing your grandkids from thousands of miles away. VoIP enables these kinds of "connections" and typically does so for a fraction of the cost of other, more conventional means.

What do you think VoIP is? Leave your thoughts in the comments.