Directions Magazine, Pitney Bowes (MapInfo), and many blogs are talking about 'CLOUD's in relation to GIS. I have read about Cloud-Computing but still don't understand the concept.
One of the key benefits of cloud computing is scalability and cost. In a cloud-based setup, you might have 1 virtual server running your GIS application (e.g. a web application showing flood events across the country).
As demand for the application rises, new virtual machines switch on/off (automatically if thats how you set things up). In the middle of the winter when a big storm event occurs, you might have a large number of machines running as millions of people login to find out whats happening...then, after the event finishes and demand falls, the virtual machines all switch off.
No need to have a huge server farm running 365 days a year, just to serve those key few events.
This type of scalability is tradiationally very expensive...e.g. if you are a government organisation with a statutory requirement to serve this type of information.
With a cloud based setup, you only pay for what you use, when you use it. So the cost for those 50+ servers (power, maintenance, etc) are massively reduced.
For some orgs (e.g. central govenrment) this could be a real cost saver (there are other issues around this though!0
Cloud computing is basically the act of moving data or computations to servers that are distributed all over the world instead of a computer that is tied to one physical location. You then use a client, such as a web browser, to access your data/computing power from anywhere that has an internet connection.
Think of it as the difference between owning a car and paying for electrical service. With a car you have to make a huge up-front capital investment and then pay for regular maintenance or else it eventually breaks down. With electrical power a utility company somewhere is managing all the details of buying and maintaing the power plant- you just pay a monthly bill and get the benefit of a service.
The core of cloud computing is the idea of moving computing away from something that requires ownership and maintenance of hardware into a utility that is paid for based on consumption.
The consequence that most people are getting excited about is that when computing power is treated as a utility that is delivered over the internet, software and data becomes accessible from anywhere in the world.