Just Make It Short

Some people call Twitter micro-blogging -- very short messages. Users can update people about what's going on, like a blog, but the messages themselves are limited in length by system constraints.

What are Tweets?

Simply put, a Tweet is a message sent on Twitter. To send or receive a Tweet, you have to create a free account with Twitter. You also need to have friends and contacts with Twitter accounts -- otherwise you're typing to the void. Of course, you could use Twitter as a blog and keep all of your Tweets public, meaning anyone could read them on your personal Twitter profile page. But if you want to use Twitter as a way to keep in touch with friends, you'll need to convince them to sign up, too.

Once you have an account, you can begin building your network of contacts. You can invite other users to receive your Tweets, and you can follow other members' posts. As you receive Tweets, you may discover you're looking into only part of a conversation. You'll see your contact's posts, but if he or she is sending messages in response to someone who isn't in your network, you won't see the other person's messages.

Tweets have a few limitations, mostly due to the fact that Twitter's design relies heavily on cell phone text messages. Tweets can only have up to 140 characters before the system cuts off the rest of the message for cell phone users. Members can read full Tweets on their Twitter Web pages or by using a third-party developer's desktop or Web-based application.

Tweets can only contain text -- members can't include pictures, video or other computer files with Tweet messages. Members who want people in their network to look at multimedia content must find a Web page to host the files, then send a message containing the page's address to their networks. Twitter converts all addresses more than 30 characters in length into tiny URLs -- links that compress the full Web site address to conserve space.

Twitter makes it easy to opt into or out of networks. If you join Twitter and find that you're being bombarded by Tweets from a particular member, you can choose to stop following his or her feed. All you have to do is send a message to Twitter that says "off," plus the chatty member's user name. Later, if you find that you miss the sender's updates, you can type "follow," plus the user's name. As long as the sender has kept you in his or her network, you'll start receiving those messages again.

In the next section, we'll learn about how Twitter's many applications.