Okay, so the phones and the computers are using the same wires and switches; that sounds good. We've created one physical network, so there have to be some cost savings here. And, we are also using the same basic protocols. Once again, that sounds like a money saver, as maintenance should be easier, and we will only need one set of test equipment.
But - wait a minute - is convergence just designed to save me money in infrastructure and support costs? No, absolutely not. Convergence is about doing things smarter, faster, and better. If the network works smarter, people work smarter, and business should grow. And that's what's attractive about convergence.
In daily business you get emails, voicemails and faxes. It is up to you to determine which to look at first. What if you decide to listen to and respond to voicemail first, and then look at my emails? An email may contain information I needed to answer a voicemail. Then you may need to send another voicemail correcting the first. Then the recipient of the voicemail may make a decision based on the first message before they get the second message. This could go on and on. However, if all voicemails, emails and faxes - and even video messages - went to a single source, like your PC screen, you could review all different types of messages at one time and make appropriate decisions based on a complete set of information. And on top of all that, I could also forward emails to voicemail, etc.
This type of application convergence is just one example of what convergence means to business - using technology to help you do your job more effectively. Convergence is treating all types of communication as just individual components of a single communications system.