The internet is a tremendous human feat. It is the first medium that truly connects all of the world at the same time, both a-synchronously or synchronously. For it to be able to work, there is an enormous hidden infrastructure all over the world, not just a cable from your computer to the web server.
On the administrative level, there are global, regional and national organisations that have the responsibility of managing the internet. The Worldwide responsibility rests upon the Internet Engineering Planning group, or IEPG for short. Their task is to support regional internet service providers and to delegate operational and administrative tasks to them. The regional operators include The European, American, Asian, Latin American and African Registry offices.
These organisations govern the network of networks that is the internet. Also commonly called a meta-network. So, thousands of networks sharing the same protocols so they can easily talk to each other. This protocol, TCP/IP is designed in a way that no matter what hardware or specs an object has, it can connect to other devices on the network. In networking terms, all nodes are equal, asserted they have the same redundancy.
The communication between devices happens on a massive scale worldwide, something which is enabled by the openness of the TCP/IP protocol. It operates on an infrastructure so vital and so essential to daily life that governments and some of the biggest corporations in the world rely on it for day-to-day operations. The infrastructure, as the administrative body itself, is divided into multiple branches that serve the same purpose on a local, regional, national and global basis. A good metaphor found here, illustrates the internet as a riverbed. Small creeks feeding into medium sized streams, into rivers that mouth into the ocean and connects everything.
Packets, IP's, servers and switches.
In massive fibre optic cables under the sea and through invisible radio waves in the air, travels small packets of information. These packets contain a "command" for the recipient, a server, and the address of said server. Firstly, just as a conventional postcard, it has to go through a lot of sorting to be sent in the correct direction and to the right address. These sorting points are called switches, routers and DNS servers. Routers are like roundabouts in traffic; it acts as a link between computers and different networks and directs traffic. Switches can have several functions, but are mainly used as something we can compare with a multi lane highway - it distributes the load. Commonly also used in conjunction with security concerns in that you can implement hardware grade firewalls in them. A DNS translates hostnames into public IP addresses and then sends the packet, translated into an IP address, in the correct direction.