What is a Server?

Watch the presentation

Se presentationen på svenska

In IT, servers provide the computing power behind applications, websites, and databases. This article breaks down the server concept, focusing on its role as a compute resource, from physical machines to serverless functions.

The Purpose of a Server

A server is a compute resource designed to process requests and deliver services to other devices, called clients, over a network. Traditionally, servers were physical machines, but now they include virtual machines, containers, and serverless functions. Despite these variations, the primary role remains the same: process workloads and deliver services.

Key Characteristics of a Server

• Processing Power: A server has CPU, memory, and storage resources to execute tasks.
• Networking: It is network-connected, allowing communication with other clients or services.
• Service-Oriented: It typically provides services, such as applications, databases, or file storage, to other systems or users.
• Flexible Deployment: A server can be deployed in different environments - on physical hardware (bare-metal), as a virtual machine, in containers, or as abstracted serverless functions.

Servers are often described by the role they play, such as a web server or a database server, but fundamentally, they are compute resources allocated to perform specific tasks.

Servers as Compute Resources

Servers come in different forms based on the level of abstraction.

1. Physical Server (Bare-Metal Server)
   A physical server is the hardware that runs applications and stores data. It offers dedicated resources and full control but requires more management.

   • Common Synonyms: Dedicated server, on-premis server.
   • Cloud Examples: AWS Bare Metal Instances, Azure BareMetal Servers, Google Cloud Bare Metal Solution.

2. Virtual Machine (VM)
   A virtual machine emulates a physical server but runs as software on a physical host. VMs allow multiple isolated environments on the same hardware, improving efficiency.

   • Common Synonyms: Instance, virtual server.
   • Cloud Examples: AWS EC2 Instances, Azure VMs, Google Cloud Compute Engine Instances.

3. Container
   A container is a lightweight, portable environment for running applications. Containers share the host’s operating system but keep application processes isolated. They are efficient and widely used in microservices architectures.

   • Common Synonyms: Docker container, microservice container.
   • Cloud Examples: AWS ECS Tasks, Azure Container Instances, Google Kubernetes Engine (GKE) Pods.

4. Serverless Function
   A serverless function abstracts away the infrastructure entirely. Developers write code, and the cloud provider automatically manages the resources. Serverless functions are triggered by specific events like API requests.

   • Common Synonyms: Function-as-a-Service (FaaS), event-driven computing.
   • Cloud Examples: AWS Lambda, Azure Functions, Google Cloud Functions.

Choosing the Right Compute Resource

As compute resources, servers are essential for running applications and services. Their form depends on the specific needs of the project:

• Physical servers offer maximum control but require significant management.
• Virtual machines provide flexibility and isolation without the overhead of maintaining physical hardware.
• Containers are more lightweight and scalable, ideal for modern applications.
• Serverless functions eliminate infrastructure concerns, allowing developers to focus purely on code.

IT architects must choose the appropriate compute resource based on performance, scalability, and cost:

• Performance: Physical servers and high-end VMs are best for demanding tasks, while containers and serverless are ideal for scalable, less resource-intensive applications.
• Scalability: Containers and serverless functions scale easily to meet fluctuating demand.
• Cost: Serverless functions are typically pay-as-you-go, making them cost-efficient for variable workloads. VMs offer predictable pricing for long-running tasks.
• Control: Physical servers and VMs provide more control over the environment, which is useful for specialized applications.

Conclusion

A server in modern IT can be a physical machine, virtual machine, container, or serverless function. Each has different levels of abstraction, control, and scalability. It’s important to understand these options to match the right compute resource with the project’s technical and business needs.