Nadiv - 2.0 - Programming Servers

Previously, we saw how we could setup a web server running nginx that could "serve" html pages that we created and modified. We then learned that using different URLs, we could access different pages and other content (like images, etc.) In fact, you could have nginx send any kind of data you wanted from a file (though there are a few small complexities that the software handles for you in the most common cases, but we will get into that later) We'll get into exactly how browsers and other software "requests" data from servers, but basically, it all boils down to HTTP (or Hypertext Transfer Protocol). We might get into the details of exactly how HTTP works later, but right now there are a few things you need to understand at a basic level. HTTP is a protocol for the communcation between "clients" and "servers" originally designed for the communication and transfer of hypertext (think HTML). Basically a client is a requestor or user of a service or resource and a server is a provider of that service or resource. The bi-directional communication of data between clients and servers forms the basis of the "client-server" model of "distributed" computing. HTTP is what is known as an "Appliation layer" protocol - meaning that it makes no specification of exactly how the raw data should be transferred between the client and the server - it is simply a specification of how to format a series of characters for the purposes of communication. We won't get too deep into how data is transmitted quite, yet, but if you're interested, HTTP typically uses Transmission Control Protocol (TCP) over Internet Protocol (IP) to communicate. - HTTP: https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol - Client-server model: https://en.wikipedia.org/wiki/Client-server_model - Distributed Computing: https://en.wikipedia.org/wiki/Distributed_computing - Transmission Control Protocol: https://en.wikipedia.org/wiki/Transmission_Control_Protocol - Internet Protocol: https://en.wikipedia.org/wiki/Internet_Protocol So,