Prevent Duplicate Request Processing

Suppose a client sends the same network request more than once unintentionally—for instance, a user double-clicks a button, a timeout triggers an automatic retry, or the network itself duplicates a packet. Your task is to design a dependable mechanism that ensures the underlying operation is executed only once, even when duplicate requests arrive. Describe both client-side and server-side strategies, and explain how your approach handles duplicates that arrive concurrently.