Cloud computing has gained significant popularity in recent years due to its self-service capability, flexibility, affordability, scalability, and pay-as-you-go service model. You may have also heard that cloud computing is known as the cloud, cloud hosting, cloud server hosting, etc. These terms have been thrown around a lot and most don’t even know exactly what they mean. So what is cloud computing?

Cloud computing is different from traditional hosting alternatives that use a single dedicated server, as cloud computing uses virtualization technology to pool or share resources from an underlying network of physical servers. In other words, a group of physical servers acts as one big server to give you the resources you need on demand. Cloud computing offers shared computing resources, data, or software over the Internet; which is the most common way to access the cloud. However, intranets and dedicated networks are also used. The resources provided by the cloud include: networks, servers, storage, platforms, applications, and other services. And these resources are shared between people and organizations, and are accessed by applications or users.

The five main characteristics of cloud computing

In cloud computing, there are five fundamental characteristics that set it apart from traditional hosting alternatives, including fast elasticity, broad network access, on-demand self-service, resource pooling, and metered service.

· On demand self service

With the on-demand self-service of cloud computing, you can access email services, applications, networks, or servers without human interaction. Simply set up an account with the seller, create billing and security credentials, and select the cloud computing resources you’ll need. Typically, this is all done using a user-friendly and easily accessible web-based self-service portal.

· Wide network access

Cloud computing services are available over a network, either through a dedicated network, the Internet, or an intranet. Anyone, anywhere, at any time, and on any device or workstation, can access these services, of course, with the correct credentials.

· Pooling of resources

Cloud computing provides multiple clients with the same physical resources, however with a separate environment for each client. And the resources of these physical servers can be pooled from multiple servers, in multiple data centers, in multiple locations. And if a server on your network goes offline, then your virtual server will pool the resources of another server on your physical network. Even if an entire data center in your network is down, your resources are pooled from multiple data centers in multiple locations. This structure allows to reduce the risk in case of failure.

· Quick Elasticity

Perhaps one of the essential benefits of cloud computing is the flexibility it provides users, as cloud resources can be provisioned quickly and elastically to quickly scale out and in to meet demand. In other words, you get the resources you need when you need them.

· Measured Service

Cloud computing takes advantage of metering capabilities to measure your resource usage, allowing you to only pay for what you’re using. In other words, just like a utility bill, you’ll only be charged for what you use, nothing more, nothing less.

The 3 main models of cloud computing services

In cloud computing, there are three main service models. They are Software as a Service (SaaS), Infrastructure as a Service (IaaS), and Platform as a Service (PaaS).

· Software as a Service (SaaS) it is the most widely used cloud computing service model. SaaS allows developers and organizations to use specific business applications developed by third parties. In a SaaS model, the provider hosts both the application and the data, and the end user can use the services from anywhere. SaaS is not your average on-premises software, as it is deployed on a network, usually the web, accessible through the browser or program interface. Services can be anything from email to inventory control to database processing. Some examples include: Salesforce.com, Zoho, and Netsuite. Service level coverage provided includes: application uptime and performance.

· Platform as a Service (PaaS) It is a type of cloud computing that provides users with software development tools that are hosted on a cloud provider’s infrastructure. In a PaaS environment, developers can take advantage of a cloud provider’s resources to build and host applications on their platforms over the Internet. The biggest benefit of PaaS is that users can run existing applications or develop new ones without worrying about maintaining server hardware, operating systems, load balancing, or computing capacity. In other words, you can offload the responsibility for owning, managing, and operating the systems software and hardware to your service provider. The types of services provided can be anything from RunTime scenario, cloud storage, integration, etc. Some examples of PaaS are Google App Engine, Windows Azure, and Force.com. Service level coverage provided includes: environment availability, environment performance, and no application coverage.

· Infrastructure as a Service (IaaS) It is a form of cloud computing that provides users with networking, storage, virtualized servers, and system software that give you all the functionality of a complete data center. In other words, you can use computers that your service provider owns, manages, and operates. Resources should span servers, storage, provider-managed network, and virtualization layers so your network architect can run your application and data. Meanwhile, you’ll have control over the operating systems and deployed applications. Types of services provided: cloud storage and virtual server. Some examples: Amazon Web Services, RackSpace Cloud, and Go Grid. Service level coverage provided includes: virtual server availability, provisioning time, and no application or platform coverage.

The top three cloud solutions

There are many types of cloud strategies to employ. There are three main types of cloud solutions, including: public, private, and hybrid cloud solutions.

· public cloud

When people think of the term cloud, most of the time they mean public cloud. A public cloud solution is shared by thousands of customers around the world and is available to anyone on the Internet. This is the easiest and most cost-effective cloud strategy to employ. However, because you share the cloud with the public, you don’t want to keep sensitive information here.

· private cloud

When your organization has sensitive data, privacy fears are a major issue. This is where a private cloud will come into use. A private cloud is a proprietary network or data center that provides hosted services to a single customer. In a private cloud setup, you must lease or supply the hardware that will be used. Not to mention, you can manage some or all of your IT resources internally or manage them externally. For companies in highly regulated industries where security is paramount, a private cloud solution is the only alternative. The benefits of a private cloud solution include: no restrictions on network bandwidth, security vulnerabilities, and legal concerns that using a public cloud might entail. It can also be more secure, accountable, and resilient than a public cloud because usage can be contained and managed. Some downsides are that it requires a large capital investment, time to market can average 6-36 months to get established, and the learning curve is great.

· hybrid cloud

A hybrid cloud is a combination of a public and a private cloud and is considered to be the best of both worlds. A hybrid cloud solution allows you to keep all your data secure in a private cloud setup, while getting high usability of web-based and mobile access to corporate applications. In most cases, a hybrid cloud solution that combines the benefits of public and private clouds works quite well for most businesses. Some advantages of a hybrid cloud solution include: you are not vendor-dependent, you minimize the risk of data loss and/or downtime, you save the additional cost of purchasing dedicated server hardware, and you get fairly reliable connectivity, even in the event of outages. One major drawback is that a hybrid cloud solution is very expensive.