What is It?

1

Switch
Hub
Modem
Router

Let’s start with the easy one: Switch
a Switch allows network devices to talk to one another. It receives information from some device, and sends that information exactly where it needs to go. This allows a computer to connect to a printer, a server or any other device on the same network.
Of course, the complexity of switch configurations can increase with the complexity of network architecture. We are able to route traffic in very specific ways, separating a network into multiple subnets (ie: separating phone traffic from data traffic).

Hub:
I don’t think anyone uses a Hub. In fact, when people use the word, Hub, I assume they’re misusing language. But if you really want to know, it’s basically a Dumb Switch. Instead of sending data where it needs to go, a hub sends data to every device connected to it. Hopefully one responds.

OK! I got it so far. what’s a Router?
Believe it or not, routers route traffic between different networks. It reads the data, and knows where to direct it. They tell your print job to go to the printer, but your google search to leave your local network to use the internet.
Enterprise networks like AT&T and Comcast have multiple routers passing traffic from the local business router to core routers to internet. In the image heading this page, my google search hits 10 routers before landing on Google.

oh. Modem?
A good home modem nowadays includes a lot of the functions that a router handles. What separates it, though, is that a modem obtains a signal from your ISP (like Comcast), and converts it into TV or Internet or phone without degrading service.

Now you’re an expert. Or are you more confused?