Cloud Computing

Cloud computing offers services to users based on on-demand self-service, broad network access, measured service, resource pooling and rapid elasticity; These characteristics promise a faster time for implementation, lower cost, superior scalability and a better end user satisfaction. These services are delivered in models known as Software As A service (SaaS), Platform As A Service (PAAS), and Infrastructure As A Service (IAAS). The first layer which is the Software As A service (SaaS) is the layer in which software applications are delivered to end users. Below is the Platform As A Service (PAAS) layer which offers a platform on which applications can be developed. The lowest layer is the Infrastructure As A Service (IAAS) layer, in this layer the physical servers and network infrastructure is offered as a service. These services can be deployed throughout the internet (Public Cloud Computing), on the intranet infrastructure, (Private Cloud Computing), in a shared community of private networks (Community Cloud Computing), or a hybrid of both (Hybrid Cloud Computing). The service deployment models are [8]:

PaaS – Platform as a Service – Cloud providers deliver a platform, including operating system, programming language, database and web servers that developers can use to develop and run their software on a cloud platform without the cost and complexity of buying and managing hardware and software.

By 2020, Forbes (McKendrick, 2012) has estimated that the cloud market will be worth $270 billion; this suggests that the market is expanding rapidly and users are becoming more aware of this feature. Many people, though, still ponder over the exact purpose of cloud computing: Cloud computing is a group of offline servers that are networked together to allow data to be stored centrally. For example, Drop box is an established cloud storage company that allows users to store documents, images and videos on their servers. This type of cloud computing is known as ‘Software-as-a-Service’, which are business applications that are hosted by the provider and delivered as a service (Hurwitz, 2010). Hurwitz also mentions two other types of cloud computing: ‘Platform as a Service (PaaS)’ and ‘Infrastructure as a Service (IaaS)’. ‘Platform as a service’ is where the consumer will create an application, using tools and software from the provider, then the provider will administer the consumer with networks, storage and servers. ‘Infrastructure’ as a service is where the provider will provide the consumer with physical computer or virtual machine.

There are three service models for Cloud Computing, SaaS (Software as a Service), Paas (Platform as a Service), IaaS (Infrastructure as a Service). It is important for businesses to fully understand the knowledge about each models before investing on Cloud Computing.

Cloud computing has become a compelling paradigm for delivering and managing services over the internet. Although it might be difficult to define cloud computing, one simple definition of the term is virtualized third-party hosting. In simple terms, instead of renting the entire or actual physical server, one rents a certain proportion of server resources. The client’s server runs within a virtual container that may be moved from a physical server to another without service interruption. Cloud computing has changed the entire landscape of Information Technology, and it is finally actualizing the long-standing promise of utility computing. This paper serves as a comprehensive overview of the cloud computing technology; definition,

There is wide range of services that could be provided by cloud providers. Based on blabla, there are 3 models of cloud services that widely popular. They are Infratructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). IaaS provides for fundamental resource for computing such as processing, servers, storage, networks and manage its physical infrastructures but costumers have control for their OS [fn1]. PaaS provides design, tools or Environment with IDE. It is usually used by software developer who wants to run their application over internet. SaaS delivers ready-use software over internet or we can called as web-based software. Cloud users neither have to maintain platform or infrastructures. These days this services gain money from advertising or user list sales for example Google mail service so users can enjoy it free.

A major shift in the way companies obtain software and computing capacity is under way as more companies tap into Web-based applications like cloud computing and Web 2.0. A host of providers including Amazon, IBM, Oracle, and Microsoft are helping businesses use the Internet to tap into everything from more server capacity to software that helps manage the workload. Assigning these tasks to an offsite location is known as cloud computing (Kroenke, 2013, King, 2008, Wardley, 2012, Hinchcliffe, 2014).

PaaS is the second type of the service layer of cloud computing. PaaS provides a platform and environment as a service over the Internet which is usually targeted to developers. The purpose of Paas is to allow the developers to build an application and services over the Internet. PaaS services normally are treat in the cloud which it can be accessed by users simply via their web browser. In order for these application to run smoothly, there needs to be platform supporting it just as powerful and flexible. Besides that, Platform as a Service also allows users to create their own software applications using tools that supplied by the cloud provider. PaaS Services consist of preconfigured features that customers can subscribe. Besides that, to subscription basis in PaaS services, users need to pay for it so that it will be works. According to (Wang, GE, PING, WU & FU, 2010), an examples of well-known PaaS is Google App Engine. Google App Engine offers the circumstance to creating Java and Phyton on the servers that hosted by Google.

PaaS provides sets of services and workflows that targets developers, who can use shared tools, technologies, processes and APIs to fast

This type of public cloud computing provides applications through the internet. Most of the enterprise application follows SaaS model. This model provides both extensive configuration and also the development environment where the customers can code and make modifications and additions.

Cloud computing paved the way to the specific type of service known as Software as a Service (SaaS) in the 1990s, as well as programs like Salesforce, which gave businesses the ability to have better “customer relationship management” (Goodrich 2013). As more SaaS programs became available, it was clear that agencies like The National Institute of Standards and Technology and Legal Cloud

Cloud computing system, which functions based on the concept of providing computing as a utility, can be defined as the method of providing resources for computing on demand, using remotely operational servers on the internet for data storage, processing data and managing data. Its equivalent to using a computer for its services, only without having to carry the hardware for it. Cloud applications, being dynamically scalable, agile and capable of running virtual applications and even an OS on a browser help in reducing costs of resource acquisition.

These private environments are made accessible via the Internet. Cloud computing provides services such as software (applications), platforms and infrastructures with a subscription-based in a pay-as-you-go model. These services are generally referred as Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS).

Platform as a Service (PaaS) is where vendors (ex. Google and Microsoft) provide servers, tools, and utilities to allow the creation of applications capable of being deployed on the internet. Users manage the applications deployed and some environment settings but not the cloud network, O/S, or servers. The only hardware required for this model is a device to connect to the service. (Dulaney & Eastomm, 2014)

Cloud computing is a model for enabling ubiquitous (present everywhere), convenient, on-demand network access to a shared pool of configurable computing resources e.g., networks, servers, storage, applications, and services that can be rapidly provisioned and released with minimal management effort or service provider interaction [1]. Types of Cloud computing models are Public cloud, Private cloud and Hybrid