A semi-automatic system refers to a mechanism that requires some manual input but can perform certain functions automatically. In firearms, for example, a semi-automatic pistol fires one round each time the trigger is pulled, automatically ejecting the spent cartridge and loading a new round without needing to manually chamber it. In other contexts, such as machinery or appliances, a semi-automatic device may require the user to initiate a process, while the machine completes the task with minimal further intervention. This design balances user control with efficiency, making it popular in various applications, from coffee makers to washing machines.