Most logic routine steps must happen are executed on the server. They retrieve or update the necessary server data, perform business logic and calculations, and then your application’s screen is redisplayed to the userre-rendered with the latest server information.
However, you can also specify client-side actions, like showing a hidden widget, which do not make requests to the server. Client-side plugins are grouped together and clearly labeled as such.
Usually, your routine is will either have all client-side or all server-side steps. However, if you mix the two, In other words, it is either a client-side routine or a server-side routine. However, sometimes it may make sense to mix the two types of steps. This would allows you to provide client-side validation or to update client-side values before they are sent to the server. Please keep in mind that all client-side steps will occur before control is passed to any the server-side steps, regardless of how they are arranged in the routine.