It defies analogy and description. It's addictive. It's useful.
Twitter, for those who haven't, which is most on PE (Planet Earth), is the website, technically, on which you post messages no longer than 140 characters.
That's short. That last paragraph, for example, was 14 too long.
I (that link is my Twitter address) continue: You post messages and share them with your "followers" who may or may not be following you. You find them (followers) by searching on the names of people you know or by seeing new names when you read the posts of others you know.
Who has time for this, you ask, and why would you bother?
1. You learn.
2. You see what others are thinking.
3. You see really new things.
4. It's fun.
5. It's an incomparable writing discipline.
Thanks to Marko Saric (no idea who he is other than that he started following me and that he is a self-described "Internet marketer" and lives in London) who "retweeted," meaning he posted again about someone else's "tweet" (as the 140-character posts are known to those in the know), we all can read a history of "How Twitter Was Born" by Dom Sagolla.
Could spend the rest of the day running this all down, including the many fascinating links just in Dom's history post but it all comes down to a certain tweet posted by Twitter's board chair/founder/once-CEO Jack Dorsey: "One could change the world with one hundred forty characters."
As a writer, the 140-character limit is its own unique challenge. Saying what you mean with so few strokes is excellent discipline. For me.
That last 'graph was 139.