Cloud computing is an alternative method to server hosting. In concept, cloud computing provides a much faster performance for web page loading when compared to standard sole server web hosting. The method of cloud web hosting changes the nature of computing from product-based to a utility on demand service.
A commonly used example of cloud web hosting is web-based email. By using a provider like MSN or Hotmail, you take the email away from a personal server storage unit and instead have them held across multiple servers worldwide. The hosting is now in control of the provider, in this case MSN or Hotmail, and you download your information from locally based servers that are in their control. This makes it faster for you to see your emails.
The reason this is called cloud computing is because the provider has their servers linked together worldwide so that information downloads for consumers in Tokyo are the same speed as in Madrid and the information available is not segregated.