Google brings up a good point: email has been around for 40 years, which is older than the World Wide Web! Therefore they posed the question: ‘What would email look like if it were invented today?’
Enough introduction, let’s get to the good stuff! Waves start out as a shared document: when you create a wave, you put some initial information (text, pictures, and attachments, etc.) on it and invite people to view it. You can invite as many people as you want, and it will show up in each person’s inbox. People can then add pubic comments or replies, send direct messages to certain users, make changes to the original text, and “instant message” with other users in real time (online users can see other people typing on a character-by-character basis). In this sense, a wave becomes more than a shared document: it can take on the role of an email, a blog post, a chat room, an instant system, and a photo/file gallery.
A user can choose to make a wave public by posting it to Blogger or embedding it on a website. Embedded waves have all of the same features that they would if they were on the Google Wave site: users can see real-time updates and all edits are immediately synchronized with all places where the wave might be located.
Google Wave is currently available to invited users only. One may request an invite on the Google Wave homepage, but don’t expect any immediate reply. Wave is supposed to go public by the end of the year, and I look forward to using it!