How The Internet Works

How the Internet Works

Bandwidth if the transmission capacity of a device
Bandwidth is measured by bitrate: the number of bits per second a system can transmit
Bitrate = 8 mbps (8 megabytes per second)
Latency is the time it takes for a bit to travel from sender to receiver

There are currently 3 ways we can transfer binary:

When you make a request to a server, it does not respond with a direct, dedicated connection.
Instead, the response consists of multiple IP packets
Each packet has a header and payload
- The header says where the packet came from and where it's going using IP addresses
- The payload is the data to be transferred
Each packet travels from the original computer to the recieving computer, but make take different routes
Routers determine the route each packet takes: it takes the cheapest available route
This makes the network fault tolerant and therefore reliable
Packets arrive at the destination. TCP looks at all packets, and if they are all present, you're good to go.
If some packets are missing, TCP won't verify. It will request the missing packets.

When a user requests a URL from their browser, the browser sends a GET request to a server that provides
HTTP stands for Hyper Text Transfer Protocol
HTTP is the language and set of rules that allows computers to send documents to one another
(This doesn't account for DNS)
Once the domain name has been translated into the server's IP address, the browser sends another GET request for the index.html and the server responds with the HTML as a string of plain text
Because the information is sent as plain text, it is easy for other people to access the information
The solution: SSL, or Secure Sockets Layer
The updated solution: TLS, Transport Layer Security
When an HTTP request is made over SSL and TLS, the server must provide a certificate that proves the website is what it claims to be
Certificates are published by a set of trusted authorities