What is a cloud server? Describing the features in a cloud vs server comparison

What does the term “cloud server” mean and what's the difference between this technology and traditional server solutions? In this article, we will define and describe this kind of cloud platform and break down the comparison into 5 categories.

What is a server & what is the cloud?

Before we start comparing cloud computing vs servers, we need to define the terminology.

First, let’s define a “regular”, physical server. A server is a computer that remotely provides data or access to programs to other devices. These devices are called “clients”: a client can be your home or work PC, phone, tablet, etc. Like any computer, a server has a specific configuration: the number of CPU cores, RAM, storage capacity, etc. However, these computing resources are usually divided into virtual machines for specific tasks, like hosting a website or an ERP system. This process is called virtualization, and it’s done with technology called a hypervisor.

Secondly, we should define “cloud technology”. Some providers on the market call their servers “clouds” only because the client accesses them remotely, and this can be confusing for new users. In reality, a cloud server is a platform that simultaneously uses the virtualized resources of many physical servers and offers a number of built-in services. In cloud computing, the resources of physical servers are combined into a pool, meaning an abstract representation of all machines in the system. Let's imagine that the cloud is made up of two identical servers with the following configuration:

• 4 CPU cores;
• 16 GB RAM;
• 100 GB of storage.

For the cloud user, these servers will not be visible as separate machines, but as a set of resources, which includes 8 CPU cores, 32 GB of RAM and 200 GB of storage. The basic unit with which cloud users work is called an instance. In principle, an instance is similar to a virtual machine; the key difference is that an instance is a slice of the whole cloud pool rather than a specific server.

To describe the features of cloud versus server technologies in more detail, let's break them down by 5 categories that directly impact the business that uses them.

Category 1. Fault tolerance

Instances in the cloud utilize a portion of the resources of multiple physical servers simultaneously. This means that if a component or an entire server fails, the instance automatically engages other available resources to complete tasks. This process happens seamlessly for the user and does not result in downtime. In addition to this key feature, a well-designed cloud uses component redundancy at the architectural level. For example, SIM-Cloud uses an n+1 redundancy scheme, which ensures that network equipment, data storage, the cloud interface, and all other elements have a backup.

Some clouds also offer a way to protect infrastructure from large-scale failures, such as power supply damage caused by a natural disaster. While such scenarios may seem unlikely, back in September 2024, Central Europe – including Germany – experienced severe floods that damaged local servers for many businesses. Fortunately, SIM-Networks data centers are located in a region with a moderate climate. Data can be distributed across multiple availability zones – independent segments of the cloud. These zones are part of a single infrastructure, but utilize their own computing resources, power supplies, cooling systems etc. As a result, a large-scale failure in one zone does not affect the operation of cloud servers in another zone.

Among traditional server solutions, clusters are the most fault-tolerant and also the closest to cloud computing. A cluster is a system of multiple interdependent servers under centralized management. Similarly to the cloud, workloads in a cluster are automatically redistributed in the event of hardware failure, and it is also possible to set up applications to use the resources of multiple servers at the same time. However, clusters have a lower level of automation, and the user still works with physical servers rather than an abstract resource pool.

As a rule, there are fewer physical machines in a cluster than in a cloud. Unlike a public cloud, a server cluster is an individual solution that is used by a single client. The main job of the cluster is to keep the services running in the event that one or several machines fail, so that a system administrator can quickly fix them. In the case of the public cloud, which distributes resources among many users, fault tolerance is also achieved through scale: there are always enough servers for the user to continue working.

Category 2. Additional features

Cloud infrastructure is not only a pool of computing resources, but also a set of tools that are responsible for various aspects of working with IT services. Let's look into these features using SIM-Cloud as an example. The SIM-Networks cloud platform consists of multiple modules, and each is responsible for a specific function. Here is what some of the core modules do:

• set up the network infrastructure of the cloud, VPNs, firewalls, create virtual networks, and more;
• store virtual drive images to install software on instances;
• distribute access rights among users through authentication;
• store data in the form of virtual blocks that mimic the behavior of physical hard drives;
• automatically create and upload backups to distributed locations of your choice;
• manage cloud resources and other modules through a graphical interface.

Dedicated servers are also referred to as a "bare-metal servers" – as a rule, server solutions do not offer the same level of automation as the cloud. Providers offer a range of additional services for dedicated servers, but many of them are not included in the rental price. For example, if the vendor doesn't offer a backup service, the client will have to set up the system themselves or look for a third-party tool. Compared to the cloud, such a system is difficult to manage: in cloud infrastructure, additional service management is carried out through a single control panel. For example, this is what this panel looks like in SIM-Cloud:

Category 3. Configuration flexibility and scaling

Flexible configurations are one of the main advantages of the cloud. To create or reconfigure an instance, all you need to do is specify the required parameters in the control panel; the process will take no more than a few minutes. This means that a user can create a machine for a specific task at any moment and start working immediately. The upper limit of scaling in the cloud is determined by the amount of unused resources in the entire infrastructure. This pool is not easily exhaustible: cloud servers are specifically designed to support the simultaneous scaling needs of multiple users.

The configuration of a physical server corresponds to its components, so scaling is achieved by replacing or upgrading hardware. In practice, this takes time and resources: for example, installing a new SSD requires money, time, and the work of a system administrator. This is not an issue for companies with relatively stable workloads that can forecast their growing capacity needs.

Flexible configurations are one of the main advantages of the cloud. Resources in this kind of infrastructure are represented as a pool, meaning an unordered set. Users create virtual machines from this set of computing resources. Each VM has the same characteristics a physical server has – CPU cores, RAM, data storage, and so on. To create or reconfigure a VM, a user specifies the necessary parameters in the control panel – the process will take no longer than a couple of minutes. This means that a user can create an instance for a particular task at any time and immediately start working.

Clustering is one of the ways to scale your server infrastructure. This method is less flexible than cloud scaling. Although the resource capacity of the cloud also depends on physical hardware, and the expansion of such a system is achieved by adding new servers as well, the main difference is in scale. It is unlikely that a company renting a cluster would maintain enough reserve servers to allow for virtually unlimited scaling. In contrast, a client renting a resource quota in the cloud server can seamlessly add or remove resources without having to think about the hardware.

Category 4. The economics of the solutions

Typically, cloud solutions are more expensive than server-based ones; however, cloud user get many more features “out of the box.” Additionally, flexible scaling allows clients to manage cloud expenses efficiently. For example, they can allocate resources for a peak season or a temporary project. Once these resources are no longer needed, you can disable them just as easily and reduce spending on the cloud.

This advantage has a downside: the public cloud may end up being economically unviable for a company. In the early stages of business development, flexibility is needed in many aspects of work. However, as a company grows, workloads tend to stabilize and become more predictable. Potentially, this makes dedicated servers or private cloud more cost-effective for certain tasks. While the cost of such platforms cannot be adjusted dynamically, they eliminate the need for a company to constantly monitor expenses. At the same time, the cloud can still be used for unpredictable dynamic workloads and integrated into a single system with a server platform or private cloud. This type of infrastructure is called hybrid infrastructure.

The server is a cost-effective tool for permanent tasks with stable workloads. If the server configuration meets the requirements of the services, this solution may be more cost effective than renting an equivalent pool of resources in the cloud. However, when choosing between these platforms, it is important to consider how much the company could save in the long run through flexible cost control, the high fault tolerance of cloud servers, and built-in features that reduces the amount of work your IT team needs to do on a regular basis.

Category 5. Security and protection measures

Security measures for the cloud are included by default: for example, hardware-based drive encryption, authentication services, firewalls, DDoS protection, and more. Moreover, reliable providers maintain specific internal processes to safeguard customer data in accordance with international standards; for instance, SIM-Networks operates under the ISO 27001 standard. However, this advantage is not exclusive to cloud platforms, as the security of any rented solution largely depends on the provider.

The basic level of protection for a physical server is limited to the physical isolation of the hardware, the provider's internal processes, and the capabilities of the data center; other security measures are the user's responsibility. It’s also important to note that hackers often exploit vulnerabilities in outdated software to gain access to data. With a cloud server, the provider is responsible for updating and maintaining the software that supports the core functionality of the cloud but is not accountable for the software on the client’s side. A user of a physical server essentially gets “bare metal” and handles the software side of the platform on their own; therefore, the client bears a greater share of responsibility for security.

Setting up a secure infrastructure based on dedicated servers is a solvable task; however, the cloud offers more protection by default. This allows you to save money and your technical staff’s time both at the stage of building the infrastructure and in the long term – the provider is fully responsible for the security measures they offer. In conclusion, the cloud is the winner in the cloud vs server security comparison, as the platform better protected than a dedicated server by default and requires less investment in security.

Cloud server vs server: which do I choose?

Choosing an IT platform for a business is a complex question where universal advice is hard to give. Every company has unique needs: depending on the business model, budget, and range of tasks, a business can benefit from either a cloud platform or a traditional server infrastructure. To simplify the comparison and summarize the key points, take a look at the table below:

At SIM-Networks, we build IT infrastructures based on any platform — cloud servers, private clouds, dedicated servers, and other solutions. If you’d like to learn more, describe your business needs, and we’ll offer a solution tailored to your requirements.

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