Network system types: peer-to-peer, client-server, cloud, cluster and more
In short: Networks can be organised as peer-to-peer (all computers equal) or client-server (a central server controls resources). Larger systems add cloud services, clusters for high availability, centralised computing and virtualisation.
Two basic models
Every network has to answer one question: who provides the shared resources, and who controls access to them? The two classic answers are peer-to-peer and client-server.
Peer-to-peer (P2P)
All computers have the same status. Each one can share its own files or printer and use resources on the others, so any computer can act as a client one moment and a server the next. There is no dedicated server. P2P suits very small networks, typically under ten computers, such as a home or a tiny office where strict security isn't needed.
Client-server
A dedicated, more powerful computer, the server, stores shared files and applications and decides who may access them. The other computers are clients. Because data lives in one place, it is easy to back up and secure. In a school, for example, students and teachers work on client PCs while only the network administrator manages the server.
| Peer-to-peer | Client-server | |
|---|---|---|
| Setup | Quick and simple | Needs planning and server skills |
| Cost | Low: no server needed | Higher: server hardware and server operating system |
| Security | Weak; each PC is managed on its own | Strong; access is controlled centrally |
| Maintenance | Every computer must be updated separately | Most tasks are done once, on the server |
| Backups | Data is scattered across PCs | Data is in one place, easy to back up |
| Size | Best for fewer than about 10 computers | Scales to thousands of users |
| Admin skills | Moderate | High: needs knowledge of server systems |
Cloud computing
Cloud computing means using computing resources (servers, storage, databases, networking and software) over the internet from a provider, instead of owning and running them yourself. You pay for what you use, much like a utility bill. If you use webmail, online document editors or streaming services, you already use the cloud every day.
Three ideas make the cloud different:
- Self-service: you create resources yourself in minutes, without waiting for hardware.
- Elastic: resources grow or shrink to match demand.
- Metered: you are billed only for what you actually use.
Why organisations move to the cloud
| Reason | Explanation |
|---|---|
| Cost | No large up-front spending on servers, data-centre space, power and cooling. |
| Speed | New servers or services are ready in minutes. |
| Scale | Capacity can grow for busy periods and shrink afterwards, close to users around the world. |
| Performance | Large providers run modern hardware in many regions, reducing delay for users. |
| Reliability | Data can be copied to several locations, making backup and disaster recovery easier. |
The three service types
- IaaS (Infrastructure as a Service): you rent virtual machines, storage and networks, and manage the operating system and apps yourself.
- PaaS (Platform as a Service): the provider runs the servers and operating system; you just build and deploy your application.
- SaaS (Software as a Service): complete applications delivered through a browser or app; you simply use them.
Read more in What is cloud computing? and the shared responsibility model.
Clusters
A cluster is a group of independent servers (called nodes) that work together and appear to users as one system, with one name and one management interface. Two common types:
- Load-balancing cluster: incoming traffic is spread across several nodes so no single server is overloaded.
- Failover cluster: if one node fails, another takes over its services automatically, keeping applications available.
Centralised computing
In centralised computing, almost all processing, storage and applications run on a powerful central server. Users work on thin clients: simple devices with a screen, keyboard and network connection but little computing power of their own. Administration and security are handled in one place, but if the central server fails, everyone stops.
Virtualised systems
Virtualisation lets one physical server run several operating systems and applications at the same time, each in its own virtual machine (VM). A layer of software called the hypervisor (or virtual machine monitor) shares the real hardware between the VMs. This cuts hardware costs, improves how fully servers are used and makes it quick to create or move systems. See virtualisation basics.
Practice
A small shop has 4 PCs and one printer and no IT staff. Which model fits, and why?
Give one advantage and one disadvantage of client-server.
Match each to IaaS, PaaS or SaaS: online email, a rented virtual machine, an app-hosting platform.
What is the difference between a load-balancing cluster and a failover cluster?
Key takeaways
- Peer-to-peer: all computers equal, cheap and simple, weak security, best for small networks.
- Client-server: a central server controls resources, stronger security and easier backups, scales well.
- Cloud computing delivers IT resources over the internet: self-service, elastic and pay-per-use.
- IaaS rents infrastructure, PaaS provides a platform, SaaS provides finished software.
- Clusters give load balancing or failover; virtualisation runs many VMs on one server.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.