How the Internet Works
What is the Internet?#
The internet is a computer network that is now based on the TCP/IP protocols to connect users with computer devices to one another.
The internet became very popular due to its decentralized nature. This means that many different entities operate their own networks and traffic that are interconnected.
The Internet Engineering Task Force, IETF, is responsible for updating the technical standards for the internet, and the Internet Corporation for Assigned Names and Numbers, ICANN, is responsible for governing domain names and IP addresses (although they do not control the information sent across networks).
IP Addresses#
The Internet Protocol assigns numbers to each device as identification to one another. For IPv4, IP addresses are made up of 4 numbers, ex: 1.2.3.4, and there is the max capacity of ~4 billion different IP addresses with IPv4.
Today, we've needed more than ~4 billion different IP addresses, so IPv6 is growing in usage. IPv6 addresses are made up of 8 segments that are hexadectets (ex: 1b2f), representing a total 128 bits (whereas IPv4 represented a total 32 bits).
Wireless Internet and the Cloud#
Internet isn't just accessed through physical wires. WiFi and Cellular networks provide wireless internet for users.
Wifi is accessed through unlicensed spectrum, electromagnetic frequencies, while cellular is accessed through cell service territories, using licensed spectrum that is auctioned to cellular providers.
Cloud computing refers to computer experiences enabled through internet services (Microsoft Word vs. Google Docs, etc). This lets the user have a more seamless and convenient experience with technology by allowing the cloud (accessed with internet) to handle technical details (file syncs, software updates, etc).
How information is transferred#
Data is transmitted across the web through packets. Packets contain headers and data. A single packet can hold up to 64 KB of data (20 pages of plain text).
Packet headers contain information about destination, length, and checksum for missing data in transit.
Web History#
The "Web" was created by Tim Berners Lee in 1991, and supported hyperlinks for browsers web pages with a single click.
Berners-Lee created the World Wide Web Consortium, W3C, to standardize the web.
Speaking of the web, users use web browsers to view web pages.
Netscape, formerly Mosaic, was the first successfuly web browser released in 1994.
Then came the giants: Microsoft's Internet Explorer, Netscapes' Firefox, Apple's Safari, and Google's Chrome.
NOTE: Although W3C manages the standards of the web, no one is required to follow those standards (even though most major browsers do). The real determinators are the companies that create the browsers.
SSL#
Secure Sockets Layer, SSL, is how web connections are securely maintained. Any messages that you send or receive from a https server is encrypted so that no 3rd party listeners can understand/steal your data.
Domain Names#
The Domain Name System, DNS, is administered by ICANN, and consists of general top level domains, gTLD, and country code top level domains, ccTLD_. Domain names give users the ability to browse the web by named addresses rather than their true IP addresses.