US What a server does
A server is a computer, or a program running on one, that provides data, applications or services to other devices over a network. The devices that ask for those services are clients: a laptop opening a shared file, a browser loading a web page, or a camera sending video to a recorder.
This split is the client-server model. The client sends a request, the server does the work and sends back a response. One server can answer thousands of clients, and one physical machine can run many server programs at once, each in its own virtual machine or container.
The word covers both the software role and the hardware. Any computer can run server software, but a machine bought as a server is built to do that job continuously, for years, without someone sitting in front of it.
Types of servers by role
Most servers are named after the service they provide. One machine often runs several of these roles.
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File server. Stores shared files and controls who can read or change them.
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Web and application servers. Serve web pages and run the business logic behind websites and internal applications.
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Database server. Stores structured data and answers queries from applications.
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Mail, DNS and proxy servers. Handle email, translate domain names into IP addresses and relay or filter web traffic.
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Virtualization host. Runs many virtual servers on one physical machine, each with its own operating system.
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AI inference server. Runs trained models on GPUs or other accelerators, for example to analyze video streams from many cameras.
Types of servers by form factor
The same server roles run on hardware in four main shapes. The choice depends on how many servers a site needs and where they will sit.
| Form factor | Shape | Strengths | Typical location |
|---|---|---|---|
| Tower server | Upright case like a large desktop | Quiet, needs no rack, room for drives and cards | Small offices, shop floors |
| Rack server | Flat chassis, 1U to 4U high | Dense, shared power and cabling, easy to service | Server rooms, data centres |
| Blade server | Thin boards in a shared enclosure | Most servers per rack, shared power and networking | Large data centres |
| Edge server | Short-depth rack or rugged box | Wide temperature, DC power, small footprint | Factories, vehicles, telecom sites |
A tower server suits a single machine where there is no rack. Rack servers suit any site with several machines and a network cabinet. Edge servers bring server hardware to places a data centre cannot reach. Large sites often mix them: rack servers in a central room, edge servers beside the lines they serve.
How server hardware differs from a PC
Server parts are chosen for uptime and data integrity. Most servers use error-correcting (ECC) memory, which corrects single-bit errors before they reach the data. Drives are often in hot-swap bays and mirrored, so a failed drive can be replaced without stopping the server. Many servers have two hot-swap power supplies, each able to run the machine alone.
Servers also carry a baseboard management controller (BMC), a small separate computer on the board that lets an administrator power-cycle the machine, watch its sensors and use its console over the network, even when the operating system has stopped. Processors such as Intel Xeon and AMD EPYC add more memory channels and PCIe lanes than desktop chips, and server motherboards are built around them with more memory slots and expansion.
Servers at the edge
More server work now runs near the machines and sensors that produce the data, rather than in a distant data centre. A vision system analyzing many camera streams, a rail depot processing train data or a factory running quality checks often cannot wait for a round trip to the cloud, or send all its raw data there.
That work runs on edge servers, which keep server traits such as ECC memory, many PCIe lanes and remote management, in chassis built for shallow cabinets, dust and wider temperatures. Our rack mount servers and edge AI servers cover that range, from 1U systems with redundant DC power to rugged GPU servers.
Quick answers on servers
Servers: common questions
Can my computer be a server?
Yes, for light use. Any PC can run server software such as file sharing or a web server. A dedicated server adds ECC memory, redundant power and remote management, which matter when the service must stay up.
What is a tower server?
A server in an upright desktop-style case. It holds the same parts as a rack server but needs no rack, so it suits a small office or a single server on a site.
What is the difference between a server and a client?
One provides, the other asks. A client requests a service, such as a file or a web page. A server receives the request, does the work and returns the result.
What is a virtual server?
A server that runs as software on shared hardware. A hypervisor splits one physical server into several virtual machines, each with its own operating system, so one machine can do the work of many.
Does a server need a server room?
Not always. A tower server can sit in an office if it has airflow and a clean power supply. Rack servers are louder and usually live in a cabinet or server room with cooling, a UPS and controlled access.
What is a GPU server?
A server built around graphics accelerators. GPU servers fit several high-power GPUs, with the power supplies, cooling and PCIe lanes to feed them, for AI training, inference and rendering.
We build servers for edge and industrial sites with the processors, memory, storage, GPUs and operating system fitted as standard, and validate each one before it ships. Tell us the workload, site and power available, and we will specify the server to match.