I'm writing this column for one simple reason: Once I get it written then the next time someone says to me "I don't get Twitter, it seems kinda stoopid to me. What is it all about?" I can direct them to this polemic and save my breath.

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To begin with, Twitter is a short message routing service – messages are limited to a maximum of 140 characters (and not 160 as Google CEO Eric Schmidt claimed at the recent Morgan Stanley technology conference. Tut, tut, tut.)

This length restriction makes "tweets" (as Twitter messages are called) equivalent to cell phone "texts" (properly called Short Message Service or SMS messages) but with a difference: Text messages are essentially one-to-one whereas tweets are essentially one-to-many.

Now some might contend that Twitter's one-to-many makes it equivalent to a blogging service (some call this microblogging), but not so. The core of social networking is that there's a commons, a shared area, wherein people communicate. Normal e-mail has no commons. Blogs have a localized commons and there's usually a specific focus to the hierarchical discussion, the post's topic, and editorial control over the thread. Twitter has a global commons and there’s no restriction (other than on length) to what is posted and no enforced hierarchy.

Schmidt also claimed: "Speaking as a computer scientist, I view all of these as sort of poor man's e-mail." Really? That's like saying you view a motorcycle as a poor man's car.

Here's the way to view these different forms of communications: E-mail is like person-to-person phone calls while blogs are like lectures with follow-up questions and discussions. But social media, such as Twitter, are like a cocktail party.

So, that's the what, now the why.

When I recently asked a friend why he doesn't use Twitter he said (he sneered actually) "Because I don't care what people are eating for lunch." This is understandable because, until you've taken the time to explore Twitter, you can't "get it."

This issue of "getting it" is much the same as when many of us old timers first encountered e-mail ("Why not just pick up the phone?") or when we first learned about texting ("That's so limited and so laborious, why would anyone bother?").