OK, let me clear up the title of this one a little. There are a wide variety of languages that you can write a script in and each language will provide a certain type of output. The main languages that I work with and the reason I use them are listed below.
PHP - Webpage generation from 'static' code segments (modules) or from a MySQL data base. PHP will also allow me to populate and \or manipulate the different tables inside a MySQL database. I am using MySQL simply because it is the most widely available on most major hosting packages, PHP will work with almost any database.
ASP - This one is for those who host their sites on a Server running Windows OS as opposed to Linux, Unix or Solaris/Sun. The main point of ASP is the ease of use and the ability to quickly create what is called a Mashup. This is where you take bits and pieces (modules) from other code writers and merge it into your code to create a script or product. The module approach is very similar to the PHP approach where you simply call to 'include' the module that you want to add.
More on scripts in the coming days.
Read more: MKWeb2 - What Types of Scripts are available?