What is CGI?
An abbreviation for Common Gateway Interface, CGI refers to the way most Web servers communicate with scripts or programs. CGI is most commonly used in forms requiring the user to input information. This data is put into an HTML form by a script and can be utilized by the programmer in various ways. Perl is the language most commonly used to write CGI scripts; all of the scripts in the CGI Library are written in Perl. CGI is not itself a programming language; it's more of a protocol for communication between the Web server and a script.
What is JavaScript?
This programming language is embedded within HTML pages and manipulates the attributes of those pages. JavaScript differs from CGI in that the former generally does not require the user to reload a page in order to execute the program. However, JavaScript has a number of disadvantages: For one, the set of functions that you have to work with is quite limited compared to most programming languages used for CGI programming. In addition, various browsers have implemented different versions of JavaScript, resulting in programs running fine in one browser yet with great difficulty (or not at all) in another. Some browsers -- notably WebTV -- cannot handle JavaScript at all. Still, JavaScript is quite useful for building dynamic Web pages, as long as you write a script that will prove compatible with most browsers. Better yet, you can borrow a script where the work's already been done for you!
