Client-side scripting involves writing programs that will attach to HTML documents and run on the Web browser rather than on the server from where the document was retrieved. Server-side scripting, on the other hand, is writing programs that will be executed on servers to generate dynamic content.
Client-side scripting allows programs to have more access to the Web browser while server-side scripting allow access to more server functions.
Since server-side scripts are executed on the server, the language used to write them is irrelevant as long as an interpreter is installed on the server. Client-side scripting however is dependent upon the user's Web browser and need to be written in a language that most browsers understand.
Client-side scripting tends to be more intensive than server scripting since it requires knowledge of a number of elements supported by most Web browsers. However, the result is more distinct elements making it more enjoyable for viewers.