According to TechTarget, Cloud infrastructure refers to the network in use, storage, servers, virtualization software, and services and management tools in use that supports the needs of a model for cloud computing. The makeup of cloud infrastructure refers to what goes on in the backend hardware. The composition usually will include multi-socket, multicore servers, storage, and local area network equipment, such as switches and routers.
The three main cloud computing deployment models are as follows: private cloud, public cloud, and hybrid cloud. A private cloud is when an organization owns the components of the infrastructure and houses them inside of its own data center. Public cloud models are when the infrastructure parts are owned by an external cloud provider. Hybrid clouds are a mixture of the two models working together, once they are working together successfully, a single logical cloud for the user is set into work.
Infrastructure-as-a-service, or IaaS, is the delivery model that organizations use to deliver these infrastructure components. These infrastructure components typically include storage and networking, and these run on dedicated internet connections. An internet connection is of course required for almost every aspect of a cloud service, it is even more pertinent for the systems running on the cloud service to be able to connect to the infrastructure. When the infrastructure is compromised, the entire service will be down.
Providers usually price IaaS as if it were on a metered basis. Rates for IaaS correspond to usage at certain levels of performance. On virtual servers, rates can vary because various organizations can use many different server sizes, and these are typically measured as an increment of a virtual CPU size and memory. Prices may also range due to overseas use and the volume of countries that use said services, and also the number of people in each country using each service. When discussing the pricing for storage, it will depend on whether or not you use SSD or HDD drives for space on the cloud infrastructure. This is also where more variation comes into effect when considering the range of use overseas, and their corresponding pricing methods.
People talking about infrastructure often become confused, and mistake infrastructure for architecture. The differences between infrastructure and architecture are few, but are also unmistakable while reviewing the definition of each word. Infrastructure pertains to the components themselves that make up a system, while architecture pertains to the design of all of the components and the relationships each component has with one another. After this difference is established in your mind, it will be easier to unconsciously differentiate between the two.