Explain the differences between Server-side and Client-side code?

As the name suggest Server side code executes on the server side. For this to occur page has to be submitted or posted back and the events that are fired by the controls are executed on the server. On the other hand client side code executes in the browser of the client without submitting the page. e.g.

In ASP.NET for webcontrols like asp:button the click event of the button is executed on the server hence the event handler for the same in a part of the code-behind (server-side code). Along the server-side code events one can also attach
client side events which are executed in the clients browser i.e. javascript events