The Client Server Relationship
How does the internet work, in simple terms
At it's most basic level, the internet is one computer talking to another. Of course the internet would not be very interesting if we only had two computers comunicating, it is the vast amount of data stored on numerous computers that makes the internet so exciting.
To best understand what is going on however lets just pretend that there are only two computers involved.
- The client computer
- The one that the web surfer is on.
- The server computer
- The one that contains the data.
The Client Computer
The biggest challenge facing the website developer is the sheer number of possible combinations of computer hardware and software.
Types of hardware include
- Desktop Computers with varied monitor options.
- Laptop computers
- Hand held computers
- Game consoles
Add to this a choice of browsers
- Internet Explorer
- Firefox
- Chrome
- Safari
- Opera
And then to further compound the situation different operating systems. And operating system versions.
- Microsoft windows
- Apple, Macintosh
- Linux
- Proprietary game OS
Web pages look different on different monitors, just like the same movie looks different on a range of television sets. And different screen sizes affect the look of the page.
The server can detect what type of device is requesting the web page, and the web designer can tailor the output appropriately.
Different browsers render the markup language differently. Although there are standards in the web industry, Internet Explorer is one of the biggest offenders for deviation from the standards. We recommend Firefox or Chrome for a standards compliant browser.
Even the operating system becomes a factor for the web designer.
The Server Computer
The server is typically a very compact computer but very powerful and optimized for a single task.
Servers are maintained and managed on server farms that house huge numbers of computers in one building.
Server farms will have a range of disaster prevention and data recovery protocols.
Servers are mounted in what is known as a rack and often operate 'headless' (they don't have a monitor attached). The most important thing from our point of view is the connection to internet.
Servers will have a much better connection than you or I do in our homes and offices.
What is an operating system
The operating system is very important piece of code, without it your computer would be not much more than a doorstop. The operating system provide very low level access to the computer hardware. It is the thing that allows various parts of the computer hardware to interact.
Examples
Windows, XP, Vista
Macintosh, OSX
Linux, Ubuntu, CentOS
Why does this matter to web pages?
Pages look different in various operating systems because fonts are not standardized across platforms.
There are only five standardized font families that can be safely used across platforms.
- SERIF
- ABCDEFGabcdefg123456
- SANS-SERIF
- ABCDEFGabcdefg123456
- CURSIVE
- ABCDEFGabcdefg123456
- FANTASY
- ABCDEFGabcdefg123456
- MONOSPACE
- ABCDEFGabcdefg123456
Colors (or colours where I live) look different on different operating systems and monitors.
Things like Flash and browser selection are limited somewhat by the operating system.