When they made the Internet public the controlling system they used us something known as IP addresses. Globally we have 5 IP address companies that control them. The original system, called IPv4 was created to only allow for 4 billion IP addresses, which is almost exhausted. Therefore, today we use IPv6 which will never run out.
The fastest way to send information around the world is through Fibre optic cables. The downside of this is that they are quite fragile, we saw this in 2008 when India and Egypt were out due to an undersea cable being “cut” in the Mediterranean.
Due to many links going into the US, it is almost impossible for an entire Internet shut down. However, some countries have government policies where they control Internet access and could switch off the Internet. This is the same when it comes to censorship of the Internet. China has a “great firewall” that blocks sites such as Facebook, YouTube and Twitter.
For the first decade of the 2000s, Microsoft’s Internet Explorer was the most popular browser. When Firefox was released in 2009, it became the most popular browser, followed now by Google’s Chrome. Chrome is now the most popular browser globally.