The sci-fi movies of the past showed the protagonist collecting a group of people to combat any external invasion on the Earth. Nowadays, this gathering is done through cloud computing. Cloud computing as described by Wikipedia is, "the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. The term is generally used to describe data centers available to many users over the Internet.”
Cloud computing enables a network of remote servers to connect over the internet without the interference of a personal computer. Depending on the needs of different needs of users, there are different types of cloud computing models.
Based on the deployment model cloud computing service models can be divided into the following four types:
- Public cloud
- Private cloud
- Hybrid cloud
- Community cloud
Based on the services a cloud model offers, it can be divided broadly into the following three parts:
- IaaS (Infrastructure as a Service)
- PaaS (Platform as a Service)
- SaaS (Software as a Service)
Based on the deployment model:
Public Cloud:
True to its name, the public cloud allows all the users who want to make use of computing resources, be it hardware or software. The whole computing infrastructure is placed in a cloud computing company that offers cloud service. But the location of the cloud remains unknown to the users. Because of its shared resources, the public cloud is excellent in performance levels but can be open to various other attacks.
Private Cloud:
As the name suggests, a private cloud is a privy to an organization or a single individual. Such infrastructure generally is managed by the organization at both on-site and off-site. They are more expensive than public clouds. But they also offer a more secure and safe remote area network. This is why it is generally preferred by companies to curb their privacy issues.
Hybrid Cloud:
As can be guessed from its name, this network is a combination of private and public clouds, depending on their purpose. To interact with customers, the public cloud can be used while keeping it secure private cloud can be used. This is used by organizations when they require high capacity and security of networks. Although it seems very effective in the beginning, certain performance issues can arise for some data-intensive and high-availability workloads.
Community Cloud:
Community cloud is used to support multiple organizations sharing resources that are part of a community. The shared resources are restricted to someone outside of the community. It can be used by the government of a single country, for example.
Based on services offered by a particular cloud:
IaaS (Infrastructure as a Service):
It is the basic building block of cloud IT and provides virtual computing resources, data storage space, and networking features over the internet. In this, all the hardware, software, servers are provided by a third party on the behalf of its users. They provide resources that can be well adjusted according to demand, so it is very suitable for workloads that are temporary or are changed at the last moment.
PaaS (Platform as a Service):
It is a cloud computing service whose main work is to provide applications over the internet. The cloud provider provides a platform for services and also hosts hardware and software operating systems on its infrastructure. This frees the PaaS users from having to install in-house hardware to run and develop an application. The users just have to log-in to use the software.
SaaS (Software as a Service):
SaaS provides a complete package of a product that is run and managed by the service provider or the vendor and is made available across the internet. This type of cloud computing with an example can be the web-based email in which we only have to send or receive emails and not think about anything else. It is very popular and generally preferred because of its compatibility, automatic updates, and global accessibility.
There are some other services under this category classified as Storage as a Service (STaaS), Security as a Service (SECaaS), Data as a Service ( DaaS), Test Environment as a Service (TEaaS), Desktop as a Service (DaaS), API as a Service (APIaaS) and others which come under the category of Anything as a Service (XaaS).