What is a server?

In computing, a server is a computer that is capable of providing a service, data, or resources from hardware and software to other devices or users, known as clients. The same computer can host several servers and provide multiple services at the same time.

Any computer can be a server, and the client can even operate on the same computer where the server is located. However, servers are usually on dedicated computers or computer networks for this purpose due to security reasons. Normally, the devices on which the server operates have higher capacities than the devices it serves. Clients usually transmit their requests to the server through a network; this may be a private one at an organization, company, or institution or an external one like the Internet.

Servers are designed to be always on and connected to the network. The most common network models include:

• Client-server: client and server are separate, and each one fulfills a specific role. This model is used by e-mail services, for example.
• Peer-to-peer (P2P): all computers connected to the network can act as either servers or clients in different cases. One example of this is file exchange systems.

What is a server farm?

A server farm is a collection of servers that work together to achieve capabilities beyond the possibilities of a single computer. Server farms are made up of a large number of supercomputers that act as servers and backup servers and which also involve installing switches, routers, and powerful cooling systems.

Server farms are expensive from a financial point of view, but they also have a high energy cost. The largest server farm in the world is located in Nevada, in the United States; it is called The Citadel and covers almost 700 square kilometers. It runs on renewable energy, which sets it apart from its main competitors.

Seven of the ten largest server farms in the world are in the United States, while the largest in Europe is located in London.

What is a network protocol?

Servers respond to customers’ requests through a set of protocols. Protocols are a set of rules that determine the way in which communication between the devices that make up a network is carried out, including communications between servers and clients.

For communication between client and server to be functional, both must follow the same protocol. In the case of web servers, for example, the Hypertext Transfer Protocol, better known as HTTP, is used.

What are the main applications of servers?

Servers can play different roles and offer various types of services depending on their specific configuration and function. Here are some common types of servers and their applications:

• Web servers: these provide websites and applications over the Internet.
• DNS Servers: they translate domain names into IP addresses to allow communication on the Internet.
• Game servers: they host online games and allow simultaneous interaction between several players in the same virtual environment.
• Database servers: these are generally used in the business field to store and manage databases, allowing access to both members of the organization and users (through customer relationship management, or CRM, systems).
• Print servers: they enable managing printing systems within a network.
• Streaming servers: they distribute multimedia content in real-time or provide stored content on demand.
• File servers: they store various types of files and allow users to access them in a secure environment through a series of networked devices or through the Internet.