Hi,

I'm having a hard time understanding the difference between these two concepts. Any pointers?

Server-side script builds the page to be sent to the client. Client-side script runs in the browser.

As Above,
Many of the effects of clientside script can be accomplished on the server
Many of the effects of serverside script can be accomplished on the client
the best design choices choose horses for courses
Server side, the page is smaller when sent to the browser = faster
client side, essentially trivial things dont tie up the server
anything to do with security, is generally better on the server(1), client side validation is a joke
but clientside scripts to point the user to irrational input data, something completely out of the park, is faster than submitting the page and getting the server response back.
the combination of Both serverside and clientside scripting, Ajax (Asynchronous Javascript And Xml) allows the javascript clientside code, to request new serverside scripts to repopulate parts of the page dynamically

(1) like any axiom it is not always true