Basic Devices in Computer Internetworking
Author(s): RenzielMiner
Last Updated: 07-29-2025
Recommended Prerequisites (click to expand)
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Computer internetworking relies on four primary types of devices: Hosts, Switches, Routers, and Firewalls. Each plays a vital role in building and maintaining a functional network.
What is a network?
A computer network is a digital telecommunications network that allows nodes to share resources. Hosts, Switches, Routers, and Firewalls are all nodes.
Client vs Server
- A CLIENT is a device that accesses a service made available by a SERVER.
- Includes devices like computers and smart phones.
- A SERVER is a device that provides functions or services for CLIENTS.
- Mostly everything can be a server, so long as it provides functions for clients.
Host (End Device)
A host is any device that either accesses a network or is accessed through a network. Common examples include laptops, desktop computers, servers, smartphones, and tablets. Essentially, if it connects to the internet or a local network, it's a host.
Switch
A switch is often the first networking device that hosts connect to. It operates within a LAN (Local Area Network), directing traffic between devices on the same local network. For example, if two coworkers in the same office want to share files, the switch handles that communication directly within the building.
Router
A router connects multiple networks together and enables access to a WAN (Wide Area Network), such as the internet. When a computer on one LAN wants to communicate with another device in a different building, city, or even country, the data passes from the switch to the router. The router then forwards the data across various intermediate networks until it reaches its destination.
Firewall
A firewall acts as a security barrier between trusted and untrusted networks. It filters incoming and outgoing traffic based on a set of rules, helping to block malicious or unauthorized data. While often considered more advanced and typically appearing in later stages or competition or network setups, firewalls are essential for protection.