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.