Http is the core technology that handles how data is exchanged over
the World Wide Web, so let's discuss that for a bit.
Http stands for hypertext transfer protocol and hails from the earlier days
of the web when computers transmitted just basic webpage information.
So what is a protocol?
Well, a protocol is simply a predefined set of rules that allows computers to
communicate and coordinate with one another in order to complete a task.
In this case, that goal is to exchange messages and
or data across the internet.
Well, how does this communication work?
Client computers, talking HTTP,
transmit messages containing specific HTTP methods, or verbs,
that convey their intention or request to a receiving computer or server.
The server receives and interprets the message, reacts, and
then sends a response back through the internet to the client.
This is a request and response exchange paradigm.
Here are some examples of the most commonly used HTP methods or
verbs used today.
Here's a GET.
Get means I'd like to get or retrieve some data from you.
Server will respond with okay, here's your information.
A post means I'd like to create some new information.
A put means I'd like to update some existing information.
Now, the server doesn't always have to respond with a thumbs up.
Maybe something went wrong.
Maybe it doesn't know what you're talking about.
And it could yield some sort of unsatisfactory response.
Delete, just simply means that I'd like to delete some existing information on
the server.
This was a quick overview of the most commonly used HTP verbs but
you can find the complete set linked below.
Typical web browsing tasks like loading Facebook or
Google.com can consist of hundreds of http requests.
What I'm want to do now is use Chrome developer tools to show you
exactly what's getting loaded into Google.com when we reload the page.
Developer tools has a number of useful pieces of information and in this
case we going to click on the network tab and I'm going to reload Google.com.
And we can see all the little things that come
loading into the page right here.
See, some of them are documents, some are images, some are scripts.
In the same way, EPI exchanges contain multiple requests, but
are often an order of magnitude smaller than loading a web page
mainly because there's so much less data and media to load.