1. Ability to rapidly provision and de-provision a service. (aka: provisioning)
2. A consumption model where users pay for what they use. (aka: chargeback and showback)
3. The agility to flexibly scale - 'flex up' or 'flex down' - the services without
extensive pre-planning. (aka: elasticity)
4. Secure, direct connection to the cloud without having to recode applications (aka: internet-based)
5. Multi-tenancy capabilitites that segregate and protect the data. (as it says multi-tenancy)

Happen to be I have been talking about 4 of the 5. Did not mention connection to internet as assumed this.