The Internet is basically a network
And Professor Evans defined network as a group of entities that can communicate even if not directly connected. So a network has a minimum of two persons/computers, and there has to be a way for these elements to communicate without direct connection. Our Internet is built in this way. When you connect to this website, you do not connect to WordPress directly. Your computer will send this request to view my website to your router, and router to your Internet Service Provider, then to the web host which hosts WordPress. There might be even more intermediate steps in between! And all these happen within seconds.
The time from your request to view this site (the time you press enter after entering the URL), till the WordPress.com receives your request is called the latency. Latency is now measured in milliseconds, which is a thousandth of a second. Eventually we might hit even faster speeds, measuring in micro seconds or nano seconds! Bandwidth is the amount of information that can be transferred in a unit time, usually a second, and it is measured in bits per second or even Mbps, mega-bits (a million bits) per second. So note the difference!