What is a Network?

What is a Network?

The goal of this blog is to provide public health experts with a pragmatic grasp of technical concepts so they can both understand their technical teams and provide effective guidance as public health increases its technical capabilities.

A digital network is a social network built using digital technologies. Perhaps one of the most familiar examples of a digital network is the way phones and computers connect to other systems on the internet. By using webs of connected computers, digital data can be exchanged or copied rapidly and accurately across great distances.

While computers and phones are modern examples of digital networks, they are not the only model of how one functions. As shown in the first two illustrations below, children in classrooms passing notes to one another or city subway systems that offer a range of options and destinations to transport travelers are both excellent, physical examples of networks that exchange information or actual people.

The internet can be thought of as a set of computers connected to each other that cooperate to send data among themselves, much like students who collectively cooperate to pass notes in the hope their classmates will, in turn, continue to pass their notes. When you visit a website or read your email, you are not directly connected to those services, but rather connected to them through a network of computers. Just as when you take a trip on a citywide subway system, you may simply say you traveled “by subway,” even though you didn’t stay on just one train, but actually changed trains once or twice along the way. What you see on the internet comes to you via dozens of computer systems cooperating to copy and pass your information along.

It is important to recognize none of the connections in these examples are direct or permanent. They all depend on the continued operation of the network. In the third illustration below, the character in the island café is connecting to the internet via Wi-Fi. But that is only the first link in the chain. The Wi-Fi then depends on a local Internet Service Provider to forward data onward to another computer that connects to a submarine cable. Submarine cables facilitate nearly all internet traffic that goes overseas. This connection links dozens of computers on the mainland before finally arriving at the destination website or email server, as shown in the last illustration.

We depend on digital networks in public health daily to connect systems and keep them linked. Understanding how a network functions will only help to continuously strengthen the connections and create more efficient ways to work together wherever we are in the world.