Difference between Virtualization and cloud computing

1. Virtualization provides flexibility that is required for cloud computing. Cloud computing can be defined based on the virtual machines created with virtualization. Virtualization is not always necessary in cloud computing; however, you can use it as the basis. 2. Cloud computing is an approach for the delivery of services while virtualization is one possible service that could be delivered.
3. Large companies that have high download speed and high security as their main requirement finds virtualization as the best option. Smaller companies focus more on their mission while leaving all IT chores to be done by others by using cloud computing.
4. Another differentiation may be the areas of self-provisioning, granular billing/charge back and APIs. Cloud was implemented more of an outsourced/hosted model first and then slowly being adopted within the enterprise firewall as an architecture. Virtualization on the other hand was started within the boundaries of enterprise firewall and then was utilized in hosted environments.
Even if there are differences and similarities many in the industry use them interchangeably