The cloud is a fancy word for the internet. There are a lot of cloud services that we use everyday:

• Google docs
• iTunes
• Zendesk
• HubSpot
• Xero

It just means that our computers aren't processing information and storing data - another server is doing that for us.

Salesforce is a cloud service for managing customer relationships. I don't store any data on my computer - it's all stored on Salesforce.com servers, and their servers are processing all of that information.