Nodes in a Computer Network Explained

Your computer and printer are both network nodes

Picture of a network of intertwined cables

William Bout on Unsplash

A node is any physical device within a network of other devices that’s able to send, receive, and/or forward information. The computer is the most the common node and is often called the computer node or internet node.

Modems, switches, hubs, bridges, servers, and printers are also nodes, as are other devices that connect over WiFi or Ethernet. For example, a network connecting three computers and one printer, along with two other wireless devices, has six total nodes.

Nodes within a computer network must have some form of identification, like an IP address or MAC address, for it to be recognized by other network devices. A node without this information, or one that has been taken offline, no longer functions as a node.

What Does a Network Node Do?

Network nodes are the physical pieces that make up a network, so there are often a few different types.

A network node is usually any device that both receives and then communicates something through the network but might instead just receive and store the data, relay the information elsewhere, or create and send data.

For example, a computer node might back up files online or send an email, but it can also stream videos and download other files. A network printer can receive print requests from other devices on the network while a scanner can send images back to the computer. A router determines what data is given to which devices that request file downloads within a network but is also used to send requests out to the public internet.

Other Types of Nodes

In a fiber-based cable TV network, nodes are the homes and/or businesses that are connected to the same fiber optic receiver.

Another example of a node is a device that provides intelligent network service within a cellular network, like a base station controller (BSC) or Gateway GPRS Support Node (GGSN). In other words, the cellular node is what provides the software controls behind the cellular equipment, like the structure with antennas that are used to transmit signals to all the devices within the cellular network.

A supernode is a node within a peer-to-peer network that functions not only as a regular node but also as a proxy server and the device that relays information to other users within the P2P network. Because of this, supernodes require more CPU and bandwidth than regular nodes.

What Is the End-Node Problem?

There’s a term called “end node problem” that refers to the security risk that comes with users connecting their computers or other devices to a sensitive network, either physically (like at work) or through the cloud (from anywhere), while at the same time using that same device to perform unsecured activities.

Some examples include an end user who takes their work laptop home but then checks their email on an unsecured network like at a coffee shop, or a user who connects their personal computer or phone to the company’s WiFi network.

One of the greatest risks to a corporate network is a personal device that’s been exploited and then used on that network. The problem is pretty clear: the device is mixing a potentially unsecured network and the business network that likely contains sensitive data.

The end user’s device might be malware-infested with things like keyloggers or file transfer programs that extract sensitive information or move malware to the private network once that connection has been established.

There are many ways to help avoid this problem, from VPNs and two-factor authentication to special bootable client software that can only use certain remote access programs.

However, another method is to simply educate users on how to properly secure their device. Personal laptops can use an antivirus program to keep their files protected from malware, and smartphones can use a similar antimalware app to catch viruses and other threats before they cause any harm.

Other Node Meanings

Node is also the word used to describe a computer file when in reference to a tree data structure. Much like a real tree where the branches hold their own leaves, the folders within a data structure hold their own files. The files might be called leaves or leaf nodes.

The word 'node' is also used with node.js, which is a JavaScript runtime environment used for executing server-side JavaScript code. The 'js' in node.js does not refer to the JS file extension used with JavaScript files but is instead just the name of the tool.