The Cloud business model centers on selling access to cloud computing resources and charging users by how much of the cloud computing resources they use. Cloud providers bill for everything from the time you have resources allocated to the CPU cycles you use to the data you send to your users.
What is a cloud resource?
Cloud resources are really anything you use to run a workload on the cloud. The definition of a billable cloud resource can vary from cloud provider to cloud provider; however, most cloud providers usually consider virtual machines, CPU usage, storage, and bandwidth as the basic cloud resources for which they will bill users.
Clouds usually bill as you go
One of the most attractive features of the cloud for many users is that you can pay as you go. You do not start paying for your cloud account until you allocate resources on the cloud, and then you only pay for the resources as long as you use them.
This is great for smaller teams or individuals who do not have a lot of money to spend on computing hardware or other necessary resources to run workloads.
Cloud providers do often offer other payment options to prepay for set amounts of cloud usage in exchange for discounts.
Many providers do offer discounts after you keep resources in use for certain periods of time for long-term usage.
Watch out for runaway bills
While the usage-based model of the cloud can be very convenient and efficient, you can easily run up a huge cloud bill if you have a program that uses up way more CPU resources than you expect.
Many cloud providers do offer tools to prevent this kind of situation, but the usage-based model does enable this kind of runaway bill if you unintentionally run a really CPU-intensive program or use a lot of bandwidth.