Cloud computing is an Internet-based system based on pay-as-you-use logic. Cloud computing provides infrastructure, software, platforms and devices to users through virtual servers. Cloud computing only rents the services to its customers and tenants pay for the time they use. Cloud computing users can better concentrate on their business without dealing with technical details. The speed of application development of customers not interested in infrastructure increases, while the cost may increase or decrease. However, when we think about the cost of the personnel who are interested in the infrastructure, it can be thought that cloud computing will be advantageous for the tenants in every situation. Figure shows services and models offered to customers within the scope of cloud computing.
1. Deployment Models
Distribution models are four types according to accessibility.
1.1 Public Cloud
The public cloud is the traditional cloud computing distributed model. This cloud is accessible to all customers via the Internet. Private cloud is more secure than public cloud because public cloud is accessible to all internet users. For example; azure.
1.2 Private Cloud
Private cloud is more secure than other cloud deployment models. It is prepared for an organization and the organization can manage all the resources it has in the cloud. Provides resources to people who determined by organization.
1.3 Hybrid Cloud
Hybrid cloud is the distribution model where general, private is used integrated. Where security is important, private cloud is used, while other areas use public cloud. Hybrid cloud is the solution according to our needs and cost.
1.4 Community Cloud
Organizations with similar needs can come together to create a community cloud. These organizations build the cloud infrastructure according to their needs. Cost is more expensive than the general cloud. But the community cloud is safer than the general cloud.
2 Service Models
Cloud computing’s service models are three types.
2.1 Infrastructure as a service (IaaS)
IaaS users can easily access many computer resources via the Internet. Storage, operating system, network, hardware, storage device are examples of computer resources. These resources are rented to users and the user pays for the time he uses these resources. Google Compute Engine, Windows Azure, Amazon EC2 are examples for IaaS.
2.2 Platform as a service (PaaS)
PaaS offers its users the application development and distribution platform as a service. Thus, users do not have to pay serious money to servers, power and equipment. They can use this service only with internet access. Force.com, Windows Azure, Google are examples for PaaS.
2.3 Software as a Service (SaaS)
SaaS is a cloud service service that allows the user to use the software via the internet. Users can use the software without installing them on their computers. Thus, users do not have to deal with software purchase, maintenance, and managing updates. Microsoft Office 365 is example for SaaS (Malik, Wani & Rashid, 2018).
3 Benefits of Cloud Computing
- Eco-friendly: It provides 30% less energy use and carbon production than local server use.
- Scalability and adjustable capacity: Allows users to shape their consumption according to their needs.
- Ease of access: Cloud computing provides easy access to all types of resources via the Internet.
- Low cost: Cloud computing enables companies to meet the services they need via the Internet, rather than building their own service infrastructures. This means less cost for firms.
- No fixed investment cost: No need to purchase hardware. You can rent for the time required.
- Flexibility and efficiency: Capacity increase and reduction can be made upon request.
4 Disadvantages of Cloud Computing
- Service continuity and availability: In the event of a problem with the Cloud Services service providers, all companies receiving service from this service provider will be affected and become unable to serve their customers.
- Data security and privacy: The use of cloud computing services by many users at the same time has risks for data privacy and security.
- Service provider dependency and data lockdown: Data loss may occur due to malfunctions and attacks that may occur in a Cloud Computing service provider.
- Remote access: Given the weakness of remote access, cloud computing has a high security risk.
- Data Transfer: When applications are starting to use more intense data, it can make it difficult to migrate data from the user to the cloud computing.
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