Now that we know what a switch is and how it primarily helps us manage network performance, it's time to learn about its companion: the device that interconnects computers on the network, we're talking about a router.
A router, as its name suggests, "routes" or, better yet, directs computer networks; additionally, they implement "gates" that provide internet access. In a business network, for example, the router allows all devices—printers, computers, phones, etc.—to access the internet simultaneously without the need to use a modem. A modem is used to connect to the internet when we only have one computer, and nowadays, most devices we have at home integrate the router and modem into a single unit, making it easy to connect to our internet provider.
The router has two IP addresses: one is public, which connects us to the service provider, and the other is private, which connects us to our network. The public address can be static (never changes) or dynamic (changes randomly according to provider configurations). Since the router is our gateway to the internet, it must have a high-security system to prevent attacks or information theft. Figure 1 shows an example of a network connection with a router.
