introduction to web (techie side)
Post on 17-Oct-2014
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DESCRIPTIONA very insightful presentation by Nick McGrath about a technical introduction to websites. It explains how a website works and where it lives.
How web sites work
An epic story of how rugbyheaven.com.au delivers important news to my screen every
What is a website and where does it live?
How does our browser find a given website?
How does our browser display a given website?
What is a database and how does it work?
What is the Internet?
The internet is like our office computer network but on a global scale
There are literally millions of computers in this networked together
Simply put the internet is an international network of computers.
What is the World Wide Web?
The www exists on the internet
Its a lose term to define the part of the internet that everyone can see and use
What is a website?
According to the wikipedia a website is a collection of related web pages, images, videos or other digital assets that are addressed with a common domain name
Lets be serious though, we all know what a website is. Weve all been to google.com, wikipedia.org or of course rugbyheaven.com.au
Do websites actually exist in cyberspace?
Websites live in specific locations on web servers
How do we find what were looking for?
With all these computers and all this information available on the www wouldnt it be great if there was a uniformed way of locating all the resources were looking for
Introducing the uniformed resource locator or URL for short
How does a URL map to a web page?
Domain names are part of a URL (http://www.rugbyheaven.com.au/news/200909.html)
DNS servers map domain names to physical machines
Finally our browser has found our site
Now our computer can open a dialogue between the browser and the web server using the request-response model
Finally a web page
This is what we expect to see on our screen
How does it happen?
A request is made to the server for a single specific file (in this case index.html)
A response is sent back to the browser in the form of HTML
Our browser reads the HTML and renders it to our screens
Why doesnt it look anything like the web site I know and love??
HTML is very simple
Yes that kind of simple
BUT it does do a couple of things very well
HTML has friends
HTML is very good at displaying text / data and linking to other resources
Links to other resources can be overt or covert
This page has been improved slightly by including cascading style sheets
HTML and Images
Its still not quite right
The Browser now needs to request all the Images from the server too
We request this
It starts like this
Trasforms into this
And finally blossoms into this
In the example we just saw there were 64 files downloaded to the browser, they were combinations of css, js, jpg, gif and swfs And it all happened so quickly
A little closer to home, on the PhotoChains homepage there are more than 130 separate files downloaded!!!
So who builds this?
Basically everything weve seen so far is built by Keong or a bunch of people like him
And if web sites / pages never changed Id be out of a job
A little bit of jargon
Server side code versus client side code
So what does server side code do?
Web pages are not all static, in fact most these days are dynamic
Servers run pieces of code to deliver different and more specific responses to the browser
Server side rarely lives alone though, its usually coupled with one or more databases (or databi if you want to impress)
What is a Database?
Think of Doms rolodex, it stores specific information
The databases we use allow us create our own structure
We now know what a website is and where it physically lives
We also know how our computer finds that website
And finally we know how a webpage gets displayed in our browser
We know what a database is and a bit about how it works
Thanks for listening, you can all be honourable techies for the day Because deep down I all know you want to be