Unified Communications come from a humble beginning. First, the invention of the telephone in 1877, then the creation of the Key Telephone System, or PBX, which allowed mass numbers to be using the phone at one time. Then the invention of the IPFX in New Zealand more than 20 years ago allowing a company to change their "presence" or availability to receive or handle calls. With the advent of IPFX, developers were pushed into overdrive to come up with a personalized system to allow companies to change these settings and handle calls without going through the phone companies. This push for individual control of communications has led to some massive leaps forward in how we do business day-to-day. With every fresh mode of communication came a new possible way of getting in touch with each other, this creating the need for products that can harness all of these new avenues of information travel.
If you were to look up Unified Communications you would get a pretty complex yet vague definition describing a single system that utilizes instant messaging (chat), presence information, telephony (including IP Telephony), video conferencing, data sharing (including web connected electronic whiteboards), call control and speech recognition with non-real-time communication services such as unified messaging (integrated voicemail, e-mail, SMS and fax). This may be a very all-encompassing answer but it may remain a little fuzzy what exactly UC is. Essentially Unified Communications can be described as any one single communications solution that can accurately tell the world who you are, what you represent, where you are, and what you can tell them. It is merely a term to define the increasingly diffuse web of communication media we use to perform our interconnected business tasks each day.
The best thing about this new technology and the countless ways in which we can access the information we need is the infinitely simpler, faster, and less painful way we can get what we're looking for, or at the very least speak to someone who can point us in the right direction.