Introduction What is cloud computing

Introduction
What is cloud computing?
Cloud computing is regarded as the area in which each independent component in order to support cloud services, often via the internet. In other words, it means you can store your information using cloud services instead of your laptop or computer. You will be able to access your documents globally by using a smartphone or laptop with any cloud service application installed on your device. (k.Chandrasekaran, 2014)
There are 3 main cloud services are Infrastructure as a service(IaaS), platform as a service(PaaS) and software as a service(SaaS) which are categorized into:
Cloud service users
Cloud service providers
Cloud service partners
Throughout this essay I will be discussing some of the main concepts of cloud computing. Some of these are the advantages and disadvantages of cloud computing, listing and explaining the various cloud service providers, the various technological drives for cloud computing, management of cloud services and various other concepts.

The advantages and disadvantages of cloud computing
Cloud services are widely known across the world by various large businesses and organisations. Although the primary motivation for cloud computing is the ability to save and view your documents no matter where you are using a smartphone or most mobile devices, there are many other advantages. Here are some advantages of cloud computing:
Accessibility: You are able to access your documents from anywhere in the world. (k.Chandrasekaran, 2014) This is very useful in cases where an employee is not at work or is on vacation and wants to access his/her documents.
Reduction in Capital cost: Businesses don’t have to worry about paying large amount to renew their software license or paying a fee per month/year. (k.Chandrasekaran, 2014)
Reducing maintenance and licensing software: Maintenance and updates become much easier as there are not much resources to be concerned about due to business/ organisation being based on the cloud provider. (k.Chandrasekaran, 2014)
“Streamline business processors” (k.Chandrasekaran, 2014): Due to not much resources to be concerned about, users can get much more work done in a shorter period. This also makes it easier for employees as their work load may be reduced.
Fewer personnel training is needed: Not much employees are needed to get large amounts of work done in a short period. Cloud platform is easy to use and requires little training to detect software and hardware issues.
You can manage projects more easily: Users can easily access their documents as each user will have his/her own cloud. Documents can also be altered if the user wants to add or delete something.

Although there are a lot of advantages in using cloud, like every other software, there are disadvantages. Here are a few:
Security: “The service provider can access the data that is in the cloud at any time”. (Anon, 2018) The security on cloud is not very strong which makes it easier for hackers to hack into a user’s cloud account.
Loss of internet connection: Another factor is the loss internet connection while a user is working on his/her documents. Without an internet connection the user will not be able to access their document or continue with the task they were originally doing. (k.Chandrasekaran, 2014)
Downtime: Although cloud allows you to access your documents anywhere and anytime, you are required to have an active internet connection. If a user is in an area with no connection, he/she will have to move to another area with internet connection. (k.Chandrasekaran, 2014)
Lack of resources: Although having not much resources are an advantage to some businesses, other large organisations may find that the software does not meet their requirements due to the lack of resources that cloud provides.

Management of cloud services
Cloud management refers to how efficient the products and services are managed in a cloud. The entire cloud relies solely on the management of the cloud. The two parts of cloud management are the management of the cloud infrastructure and managing the cloud application: (k.Chandrasekaran, 2014)

Management of the cloud infrastructure: The cloud infrastructure is known as the backbone of the cloud and is the component responsible for the Qos factor (k.Chandrasekaran, 2014). If the services or products of the infrastructure are not properly handled, this may result in the cloud failing or not functioning properly. The infrastructure of the cloud is complicated and has a lot of resources which are distributed among the users. “Poor resource management may lead to several inefficiencies in terms of performance, functionality, and cost”. (k.Chandrasekaran, 2014). Cost is the one of the main reasons for the development of cloud applications as this helps to reduce certain aspects of a business, helping them to save money.

Managing the cloud application: Due to the everlasting increase in software and technology, businesses and organisations look to move their applications on a cloud platform as it may be more efficient and easier to manage but with this move also introduces new problems for the organisation. (k.Chandrasekaran, 2014) This results to the development of applications becoming increasing more difficult than usual and also may require you to purchase more storage on your cloud. (k.Chandrasekaran, 2014) Organisations should evaluate the application and take into consideration all the factors before installing new software.

Different types and tenancy of cloud services
“A tenant is any application, either inside or outside the enterprise, that needs its own secure and exclusive virtual computing environment.” (Anon, N.d.) It can be either a public or private cloud and is usually associated with the three deployment models. Multitenancy is a software as a service(SaaS) model and refers to the distribution of the same code among several users. Developers

The nist definition and the 5-4-3 specification of cloud computing
According to the NIST definition, “Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources.” (Anon, 2011) This cloud model can be used by any electronic device such as a laptop, personal computer(pc), smartphones, etc. The cost of the cloud depends mainly on the user, meaning that cloud operates on a pay-as-you-go model which charges users according to their usage. (k.Chandrasekaran, 2014) The NIST definition also offers the 5-4-3 principal:

– The 5-4-3 principals of cloud computing:
This model consists of five necessary characteristics, four deployment models and three primary service models:

– Five necessary characteristics:
On-demand self-service: The consumer can independently determine server time and network storage as he/she needs without contacting each service provider. (k.Chandrasekaran, 2014)
Broad network access: Users can access the internet by using various devices such as smartphones laptops and PDAs.
Elastic resource pooling: Cloud service providers must have extensive resources to meet the provider (k.Chandrasekaran, 2014)
Rapid elasticity: Must support any changes.
Measured service: Storage, processing, bandwidth and active user accounts can be measured and controlled by customers and providers. (k.Chandrasekaran, 2014)

– Four deployment models:
“Deployment models describe the ways with which the cloud services can be deployed or made available to its customers.” (k.Chandrasekaran, 2014)
Private cloud: This model is usually run by a single organisation and can be either on or off premise.
Public cloud: This model is open source and is accessible to everyone through the internet. It is usually an on premise provider. (k.Chandrasekaran, 2014)
Community cloud: “The infrastructure is shared by several organisations”. (k.Chandrasekaran, 2014) The organizing principal may change but each organisation within the cloud share the same concerns. (Anon, N.d.). It can be on or off premise.
Hybrid cloud: The hybrid cloud is a combination of two or more clouds, usually public and private. (k.Chandrasekaran, 2014)

Three primary service models:
Cloud SAAS: Allows users to access any cloud application over the internet which can be either free or of a subscription fee and is aimed at the consumers. (Anon, N.d.)
Cloud PAAS: PaaS allows for developer to develop their own applications and run in on the cloud platform without the cost and effort of buying new hardware and software (Anon, N.d.)
Cloud IAAS: Works together with the Saas and “requires more management from the customer’s side”. (k.Chandrasekaran, 2014)

saas, iaas and paas(spi)

Software as a Service(SaaS): Allows users to access any cloud application over the internet. Is usually known as a “on-demand software” which can be either free or of a subscription fee and is aimed at the consumers. The SaaS model grants the user permission to run applications and services on the cloud through the internet. (Anon, N.d.) The user does not need to install applications on their computer as they are already made available within the cloud. It allows for the increase in the number of machines when needed without interfering with the normal setup. The work load is shared among these machines and is managed by a single computer as a access point (Anon, N.d.). The subscription fee is usually a per-year price plan so the pricing may differ for new users over time. Examples of the well-known service providers are Google Apps, Microsoft office 365 and Saleforce.com. (k.Chandrasekaran, 2014)

Platform as a Service(PaaS): This is a third-party service aimed at developers. PaaS allows for developer to develop their own applications and run in on the cloud platform without the cost and effort of buying new hardware and software. (Anon, N.d.). It has no need for installing of a resources for the development of a new application because its own infrastructure is managed by the developers. (Bigelow, N.d.) . The three ways that developers can acquire access to the cloud are through the “web CLI, web user interface(UI), and integrated development environments(IDEs)”. (k.Chandrasekaran, 2014)

Infrastructure as a Service(IaaS): Refers to “the ability given to the infrastructure architects to deploy or run any software on the computing resources provided by the service provider”. (k.Chandrasekaran, 2014) The Iaas works together with the Saas as it is the foundation of the three cloud models. Users can rent the amount of space they require from an Iaas provider rather than purchasing space from another datacentre which may cost them more. (Anon, N.d.) Like SaaS, Users are only charged for the services they use. The four services that are available on the Iaas platform are storage, compute Network and load balances. (k.Chandrasekaran, 2014)

Various Deployment models
Deployment models refers to the various ways in which cloud services are made available to the user, “depending on the organizational structure and the provisioning location.” (k.Chandrasekaran, 2014). There are four various deployment models. These are private, public, community and hybrid cloud services:

Private: Refers to a cloud infrastructure that is mainly run by a single organisation and may be controlled by an internal or third-party. (Anon, n.d.) This is usually the smallest of these four clouds and is not used for public use. The security on the private cloud is good as it is run by a single organisation therefore reducing the chance of being hacked into or information being leaked. Due to it being run by a single organisation, there is full control and no need to depend of other organisations. (k.Chandrasekaran, 2014)

Public: “The public cloud is the cloud infrastructure that is provisioned for open use by the general public.” (k.Chandrasekaran, 2014) This is made available to everyone as a user can buy any material they want using a public cloud. These can either be made freely to purchase or on a pay-per-usage model (Earls, N.d.), which charges the user based on their usage of the resource. The major difference between private and public computing is security. The security on public providers may be very little when on purchasing from a non-trusted network. (Anon, N.d.).

Community: Refers to “a specific community of consumers from organisations that have shared concerns”. (k.Chandrasekaran, 2014) . The organizing principal may change but each organisation within the cloud share the same concerns. (Anon, N.d.) It is an infrastructure which can be run by on or off premise organisations, internally or by a third party. The community cloud is usually a combination of different organisation, therefore the control is shared over the organisations. There is a chance of information being leaked due to the control being shared between organisations. (k.Chandrasekaran, 2014).

Hybrid: The hybrid cloud is a combination of two or more clouds, usually public and private, “that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability”. (k.Chandrasekaran, 2014). Although the hybrid cloud contains usually contains the private cloud, it also usually contains the public cloud. This makes it more secure than the public but not as secure as the private cloud.

This illustration shows the four deployment models mentioned above.

Popular implementations of cloud services

9. the various technological drives of cloud computing
Cloud computing applications are usually based of a pay-per-usage fee which saves in businesses. There has been an increase in cloud computing in businesses in recent years. This can be related to the technological improvements implemented throughout several places. (k.Chandrasekaran, 2014) Some technological improvements are “Service-Orientated Architecture(SOA), multicore technology and memory and storage technologies”: (k.Chandrasekaran, 2014)
Service-Orientated Architecture(SOA): Refers to a set of services which work together to meet a specific requirement when necessary. It has the ability to take part in data transfer or coordinate two or more services if required. (Anon, N.d.) SOA allows for the transfer of information without needing to download more resources or applications. (k.Chandrasekaran, 2014) Here are some of the benefits of SOA:
Reusing of services: It allows for the reuse of several services which helps reduce costs and also serves as a benefit for marketing purposes. Below is an illustration of reusability between the application and services: (Kumar, 2013)

Provides agility: Due to the enterprise using various web services and the ability of reusing services, the SOA enables agility in an enterprise which helps in quick changes in the system when needed rather than rebuilding the system. (k.Chandrasekaran, 2014)
Monitoring: “It helps to monitor the performance of various services to make the required changes”. (k.Chandrasekaran, 2014)
Multicore technology: This is the process of various CPUs function collectively on the same chip. It improves the performance of the system and allows the system to process more activities at once. Multicore technology can be used on many devices and also help the reduce power consumed which saves an organisation money. (k.Chandrasekaran, 2014)
Memory and storage technologies: There are more organisations being unstructured. It is relatively faster than structured data growth due to the fact that “50% of new storage requirements are consumed by unstructured data such as email, instant messaging, mp3 player and satellite images” (k.Chandrasekaran, 2014). Here are some requirements that should be taken into consideration:
Reducing the performance issues: The performance issues should be reduced as much as possible and should be monitored and controlled regularly.
Data transfer rate: The high data transfer rate should be taken into consideration as the system must be able handle high bandwidth. (k.Chandrasekaran, 2014)

10. Cloud architecture
Cloud Architecture refers to the “overall cloud computing services and solutions that are implemented in and across the boundaries of an enterprise business network”. (Anon, N.d.) The whole cloud attempts to give users full access to their applications through the internet with fast, reliable internet connection. (Anon, N.d.)The cloud solely relies on an active internet connection in order for it to operate. (k.Chandrasekaran, 2014) .

Cloud architecture is categorized into four different layers as shown above. Each layer has specific functions:
User/Client layer (layer 1): This layer mainly consists of the users and is where an active internet connection is established. Users can activate an internet connection using any device which are able to use internet services. Some of the common devices that can be used are laptops, computers, thin or thick client applications and handheld devices. (k.Chandrasekaran, 2014)
Network layer (layer 2): “This layer allows the users to connect to the cloud”. (k.Chandrasekaran, 2014) The cloud can be either public or private but the entire cloud completely relies on the connectivity. The public cloud is more accessible than the private but the user does not have access to the location. Private cloud are usually accessed through a LAN. (k.Chandrasekaran, 2014)
Cloud Management layer (layer 3): The cloud management layer is mainly responsible for maintaining the software that the cloud operates. The SLAs are close to the cloud management layer so the ongoing tasks also have an effect on the SLAs. (k.Chandrasekaran, 2014)
Hardware Resource layer (layer 4): This layer “consists of provisions for actual hardware resource”. (k.Chandrasekaran, 2014) This layer plays a vital part which controls the SLAs. Similar to layer 3, this function occurred affects the SLAs. There can be several data centres in a cloud which use fast speeds for the transfer information to the manager. (k.Chandrasekaran, 2014)

11. what is windows azure?
Also referred to as Microsoft azure, is a public cloud which provides various services in which the cloud uses to improve existing applications or to develop applications. It is “considered both a Platform as a service(PaaS) and Infrastructure as a Service(IaaS) offering”. (Anon, N.d.) Some of the main services that windows azure offers are:
Development: This helps the developers to manage applications and services more efficiently, evaluate any risks and also supports various programming languages. (Anon, N.d.)
Management and security: This application contains services which help identify and deal with any risks found within the cloud. It also helps control the flow of tasks or projects. (Anon, N.d.)
Internet of Things(IoT): This services gathers information from phones, laptops and other platforms, and examines the information collected. (Anon, N.d.)
Web and mobile: Has the ability to “support the development and deployment of web and mobile applications”. (Anon, N.d.)
Since Windows azure is a public cloud, it also serves as a benefit to businesses as they can be used as backups and data centres are made widely available for businesses to purchase if needed. Other examples of public cloud platforms are the Google cloud Platform and Amazon Web Services(AWS). (Anon, N.d.)

12. conclusion
In conclusion, cloud computing is an online application, available to everyone and can be accessed through the internet using any mobile device. (Tarzey, 2010) It has various advantages and is becoming increasing more popular but there are some important issues that need to be addressed such as security and privacy concerns. (Anon, N.d.) Large businesses and organisations should fully understand the limitations and offerings of cloud services before moving to a cloud platform.
Although there are some storage issues and security concerns, the world is becoming more modern in terms of technology and cloud computing helps businesses save money. It has not only well-known in the market industry, but also has captured the interest of users, CPPs and businesses. (Latif, et al., N.d.) I would like to say that cloud computing is a major benefit in various businesses and should be made aware of the advantages and disadvantages before being implemented in their business.