What is Cloud computing?

If you can’t or don’t want to set up your own data centre, cloud computing is the answer. This computing model offers several advantages that are attractive to individuals and international corporations alike. But what exactly is cloud computing? We take a look at this computing model and explain its advantages and disadvantages.

What is cloud computing?

Setting up your own data centre is time-consuming and costly. In addition to needing specialists for its setup and maintenance, you can’t scale it according to demand. As a result, more resources are often made available than are actually needed, making the whole process quite inefficient.

Cloud computing solves many of these problems. Instead of purchasing, installing and maintaining the technology themselves, companies and individuals use web services that are hosted by a single provider. In this way, users benefit from economies of scale as well as the ability to scale their capacities quickly, easily and dynamically. In most cases, this form of modern outsourcing runs via a rental model.

When it comes to cloud computing, services offered can vary from cloud storage space facilitated by remote servers to having infrastructure in the cloud, where users gain access to entire data centres over the internet.

According to a paper by the National Institute of Standards and Technology, services must fulfill certain characteristics in order to be referred to as cloud computing:

• On-demand self-service: It should always be possible for users to independently request the resources they need without having to contact the service provider.
• Broad network access: Cloud computing must be accessible over the internet and through standardised mechanisms and protocols that ensure widespread accessibility.
• Resource pooling: Pooling multiple computing resources is a basic requirement for cloud computing. This is done in the form of server farms, which dynamically assign and reassign resources, such as processing power and storage, to satisfy the demands of multiple users. Customers may not know the precise location of the resources they are using.
• Rapid elasticity: The delivery of capacities must be fast and needs-based. In some cases, scaling may happen automatically without users or service providers needing to intervene.
• Measured service: Cloud service use is monitored at all times, creating greater transparency for both providers and users.

Similar to how a power station is the centre of a power grid, cloud computing is usually also centred around a large data centre or a server farm, where the resources of multiple computers or servers are pooled together. This is known as grid computing and enables high performance. In combination with virtualisation, individual virtual instances can be created for users within the network. The network access works seamlessly, so the user doesn’t have to know precisely where their data is stored.

What types of cloud computing are there?

There is now a wide array of cloud solutions on the market. Besides the price and support provided, these options differ mainly in terms of the layers offered and the deployment model. The term ‘layers’ refers to the scope of the service, and the deployment model identifies the type of cloud.

Service model

A layer corresponds to a specific service level, and the various ‘as a service’ levels, or layers, describe the scope of the service. They are usually presented using a pyramid model. Infrastructure as a service has the largest scope, while software as a service focuses on specific applications.

• Infrastructure as a Service (IaaS): On this level, providers offer complete hardware solutions: processing power, storage space and network technology. The instances available to the user are completely virtual and divided into the resource pool. IaaS can serve as a basis for further layers but is also offered as a standalone product.
• Platform as a Service (PaaS): This layer goes a step further by providing a complete cloud environment rather than just hardware. PaaS primarily caters to software developers. Service providers offer a ready-to-use development environment in the cloud, hosted on their hardware. Consequently, programmers save both time and money by not having to establish and maintain the environment themselves.
• Software as a Service (SaaS): At the highest layer, users are offered software solutions from the cloud. SaaS is mainly intended for a typical end user, since they don’t have to worry about installing and maintaining software, and have the reassurance that the hardware is sufficiently powerful. To access the software, users either use a web browser or a limited program that loads the software from the cloud.
• Everything as a Service (XaaS): In addition to the three layers mentioned above, providers also offer other services. However, in this case, as-a-service terminology is often used for marketing purposes. A XaaS can generally always be attributed to a different level or may even have nothing to do with cloud computing. For example, Humans as a Service (HuaaS) is simply a form of crowdsourcing where a group of people perform tasks over the internet.

Deployment models

The deployment models indicate whether the instances are reserved for just one customer or shared with others. Deployment models are categorised based on whether a cloud is shared and who it is shared with.

• Private cloud: The servers are used exclusively by one customer. A private cloud can be on-site (internal cloud) but doesn’t have to be. Even with a hosting provider who uses a server farm, it’s possible to use dedicated hardware which other customers cannot access.
• Community cloud: The community cloud functions similarly to a private cloud, except that multiple people share a dedicated hardware instance. However, the pooling of users is not done at random. Instead, customers from the same business fields or with similar interests are often grouped together. Furthermore, the community cloud can either be managed in a company or externally. The objective is to save resources compared to running multiple private clouds.
• Public cloud: This type of deployment model corresponds to the actual idea behind the cloud. That is, you share a server connection with the general public. As a user, you cannot view or alter who else is able to use the server resources.
• Hybrid cloud: This model is a combination of a private cloud and public clouds. This means that a company or an individual can determine which parts of their operation to make private – security aspects for example – and which to leave public.

What are the advantages and disadvantages of cloud computing?

Cloud computing has significant advantages, especially for small to medium-sized organisations. For such enterprises, establishing an IT infrastructure is costly and requires continuous support and maintenance from dedicated staff. In addition, it’s best for a data centre to grow proportionally with the growth of the organisation itself. Since this is traditionally difficult to achieve, companies tend to buy new hardware in set cycles based on an estimate of their future needs. This often leads to more resources being purchased than are actually needed.

In addition to scalability, cloud computing offers further advantages. Professional server farms, such as those used by cloud providers, are much more secure than most organisations can manage on-site. Dedicated security personnel and server specialists protect the data centre from physical and digital attacks respectively, and fire safety experts ensure data is safe from fire. Finally, most cloud computing service providers conduct compulsory backups of all data.

However, cloud computing also has some drawbacks, which is why some have still not made the switch. Generally speaking, you are dependent on the provider and their configurations. If they are having technical difficulties, it will directly affect your operations. Furthermore, cloud computing requires a strong and stable internet connection to be effective and to ensure that employees can work efficiently.

The largest concern when it comes to cloud solutions is data privacy. Although it’s true that data is secured in the data centre or server farm, transmitting that data over the internet always presents a security risk. Furthermore, the location of the data centre is also critical. If the data centre is located in the U.S., for example, the cloud provider is obliged under the Patriot Act to hand over data to U.S. authorities on request. It is therefore understandable that many people are hesitant when deciding whether to use cloud computing or not.

Advantages of cloud computing

• No acquisition costs
• No capital commitment
• Scalable as required
• No in-house specialists required
• Data centres are well maintained and secure

Disadvantages of cloud computing

• Requires stable and fast internet connection
• Concerns about data protection
• Dependency on the provider (vendor lock-in)
• Security risk during transmission
• Low individual prices make it tempting to book more resources than you need

When did cloud computing begin?

Networking computers to provide users with more processing power and storage space is not a new concept. Computer mainframes in the 1950s had already taken a step towards cloud computing. At that time users could access the mainframe computer via several other terminals in the organisation (in companies or universities) and use their capacities. However, this was initially on a timeshare basis, where users had to reserve times to use the computational power of the mainframe.

In the following decades, virtualisation was developed, which allowed computer instances to be recreated abstractly. Finally, with the invention of the internet, such virtual environments were made available online and became commercially available to greater numbers of users in the 1990s.

At this point, the concept of the cloud became more popular, but it wasn’t until the turn of the millennium that companies and private individuals began to become increasingly interested in the technology. The first cloud offers were individual services, such as a space to share files or Google Sheets and Docs, where multiple users are able to work simultaneously on a document. However, at the same time, Amazon also began to provide its enormous server farms to other users. Known as Amazon Web Services (AWS), it allows other companies to use the e-commerce giant’s infrastructure and run software on it.

Nowadays, cloud computing is part of everyday life for many people. Most smartphones (or more broadly, the Internet of Things), are continuously connected to the cloud. For example, photos that users take with their smartphone are uploaded automatically to Apple or Google’s cloud service, making it possible to access them from other devices.