First off, we are talking specifically about development. For every website there are 3 key skills - development, design and marketing. Development is the techy bit in the background, design is how it looks on the front end and marketing is the content. Sometimes there is a crossover between the three skills, especially for smaller businesses.
I'm a programmer/developer, no flair for design but I can do a bit of online marketing.
How does a web program work?
Basically, a program or script, is a text file with a bit of programming code. The file extension is usually the name of the language being used, eg .php, .jsp, .py, .asp. The file sits in a folder on a web server somewhere. When browsing a website, you can sometimes tell which scripting language is being used by the extension in the web address (url). Although using technical wizardry (rewrite) this is often replaced with what looks like a series of folders and a .html extension.
So here is the basic program flow. You browse a website asking for a list of products.
When the browser (client) asks for a list of products, the request goes to a web server which processes the script file - the script will get a list of products from a database then transforms the results into a format that is readable by the browser - eg: html.
Which scripting language?
So now you know a little bit about how scripting works - which language should you use? The main scripting languages are ASP, Perl CGI, PHP, Python, JavaServer pages (jsp) and Ruby.
|asp, perl, php, python, jsp, ruby Job Trends||ASP jobs - Perl jobs - PHP jobs - Python jobs - JSP jobs - Ruby jobs|
As you can see from the job trends - PHP, Python and Ruby are increasing in popularity. Salaries for Python and Ruby are generally 10% higher than PHP but PHP is far more popular so this increases your chances of work.
Python and Ruby are *generally* used for web applications rather than websites. PHP is used for both. Although you'll pleased to know that Python has a similar syntax to PHP.
All the languages are open source and free, except ASP which is owned by Microsoft - technically ASP scripts are free but they require Microsoft software to work : a web server (IIS) and a database server (SQL Server) - so that rules out ASP for me - although I used to be an ASP developer until it was changed to ASP.Net - then I switched to PHP.
And finally, you'll find the majority of open source web applications use PHP - Joomla, Drupal, Wordpress, Magento. SugarCRM, Moodle, etc.
So PHP is the one for me!
(split the post up because its a bit long - see part 2)